Aquaculture: How German Preservice Teachers’ Perception Interacts with Values, Knowledge, and Conceptions of Environmental Concern When Making Purchasing Decisions

Abstract

Responsibly using resources is an essential goal of the 2030 agenda. An overall need for 180 tonnes of fish per year is pushing the limits of sustainable fishing. Teachers can focus on this topic to enhance the environmental awareness of sustainability issues in learners (e.g., sustainable consumption, production, and supporting sustainable judgements). For this purpose, we developed a questionnaire on the topic of aquaculture using LimeSurvey and administered this survey to preservice teachers. The survey contained five open questions relating to aquaculture terms, a semantic differential with 14 adjective pairs that concern the interest in and usefulness of aquacultures; the environmental motives scale to determine the environmental concern of the teachers, and a self-developed set of items on systems—consumption knowledge, and social influence. Individuals in the target group (n = 158) indicated that they thought aquaculture products were rather useless and uninteresting, and they purchased them less. The results showed that the participants mostly correctly defined the aquaculture terms, but an overall understanding of system- and consumption-related knowledge, for example, was missing. Aquaculture seems to be associated more with profit than with nutrition or environmental concerns. We illustrate a possible barrier to the communication of less-familiar issues in society.

1. Introduction

1.1. Environmental and Educational Approach

Nelson Mandela postulated that “education is the most powerful weapon we can use to change the world” [1]. Regarding the discourse on environmental topics, knowledge alone is not sufficient to provoke an ecological lifestyle, as it does not automatically lead to action [2]. To enhance education for action, political initiatives on environmental education have been occurring since the 1970s, when OECD member states began to include environmental issues in their school curricula [3,4,5,6]. Since then, cognitive, affective, and psychomotoric aspects have been included, and a variety of methods and ideas are present in modern learning settings [7,8]. After the first UN decade (2004–2015), the United Nations defined 17 sustainable development goals (SDGs) and 169 parameters for a global framework for all nations [3]. These goals enhance agreements from earlier international contracts [4,5,6] regarding current worldwide issues and specific objectives. The reason that environmental education began is because pedagogues, psychologists, and sociologists observed that environmental awareness was not being promoted in spite of environmental education occurring in the 1970s. Some problems have been reduced (e.g., FCKW, DDT, and acid rain), whereas other problems have been enhanced (e.g., light pollution, microplastics, forests dying, and air pollution). Currently, the term environmental awareness is perceived by some scientists as environmental knowledge, attitudes (values), and environmental behaviour, which can influence each other (e.g., [9,10]). To measure attitudes, a couple of scales were developed in the last few decades. The environmental motive scale (EMS) [11] is a widely used instrument that is used to explore environmental problems in terms of three factors: egoistic (one’s own welfare is higher than other forms of life), social-altruistic (appreciation of other groups of people), and biospheric (appreciation towards all living forms) concerns (e.g., [12,13]). Within the Campbell paradigm [14], environmental awareness behaviour patterns are more likely to emerge if a person highly values the environment. Behaviour patterns are explained according to the attitudes that a person has towards the environment and the cost of acting (e.g., a person may switch off the light because they have a positive attitude towards the environment or because it can save money). In total, two ethical views have been established: (i) anthropocentric (utilitarian) preferences, which are found in humans who tend to exploit natural resources (e.g., they protect honeybees because of pollination and honey extraction [15]), and (ii) physiocentric (biocentric and ecocentric) preferences, which concern the value assigned to nature [16,17]. Bipolar scales are used in semantic differential surveys and are grouped according to these two domains, and these surveys can be used to detect the beliefs, attitudes, and perceptions of individuals towards the environment (e.g., [18,19]). The instrument was proposed by Osgood, Suci, and Tannenbaum [20]. Different dimensions are used to answer questions, as was shown by the authors of a recent study on the digital learning environment, whereby they answered the following question: “what correlation can be found between knowledge gain in on-site and online teaching modules and attitudinal preferences measured with a semantic differential?” The main categories were protection and sustainability, and the content related to items such as hard or easy, boring or interesting [21].

After the first UN decade, the embedding of environmental issues in school lessons partly failed. The 2030 agenda declared that a new understanding of global growth and prosperity will be established and expressed in the SDGs to ensure a sustainable basis for the future. Kindergartens, schools, and universities are institutions that can contribute to a more sustainable society. The whole institution approach involves all actors participating: canteens in schools can offer fish and seafood products from sustainable farms; educators (kindergarten and in-service teachers) can impart the values and skills needed to assess sustainable food; and finally, parents can be the role models that promote healthy and sustainable nutrition. With the whole institution approach, five core principles (coherence, continuous learning, participation, responsibility, and long-term commitment) are characterised [22]. Holst summarised the seven areas of action (governance, curriculum, campus, community, research, communication, and capacity building) that underlie an organisational culture and the critical conditions needed to successfully implement ESD. The conditions are more complex than just a learning concept. Preservice teachers (PSTs) are the next generation of teachers. They must be able to develop appropriate skills and attitudes during their studies to teach students different issues. Cross-cutting issues such as education for sustainable development (ESD), inclusion, heterogeneity, intercultural skills, language-aware subject teaching, and digitisation, for example, are becoming more important in university education. This is a large challenge because universities are structured according to established disciplines. Self-efficacy beliefs are important for PSTs to provide ESD [23]. This is in addition to other variables, e.g., intrinsic motivation and self-determination, which are the basis for successful learning. Including ESD issues seems difficult (e.g., [24]) after collecting data in seven industrial and developing countries (Brazil, Serbia, Latvia, South Africa, Spain, Syria, and the UK), Filho et al. found that ESD has not been sufficiently integrated into university transformation [25]. In Germany as well, ESD is only slowly increasing in German schools and higher education [26]. Structural barriers and drivers are the reasons why ESD has not been implemented. By contrast, a couple of international examples exist whereby sustainable development has been enhanced in higher education (e.g., [27,28]). Within the teaching profession, PTSs have the important role of combining theory and practise (school).

Relating to the Lower Saxonian curriculum, all schools have had to include ESD topics in each subject (e.g., biology, math, and physical education) since June 2021 (due to the ESD decree) [29]. To achieve this aim, the state government divided all subjects (science, technology, engineering, and mathematics (STEM), humanities, and social science) into two areas of focus: practise-oriented skills [30] and global development (which involves recognising values and making decisions). The aim is to establish students as active participants in social processes that have self-responsibility, as well as to ensure that they protect the environment. Like a central leverage, PSTs can bring ESD topics into school, and they have to obtain different competencies and skills (e.g., thinking about the system, values, futures, and collaboration competencies) to teach students [31].

Before asking oneself how to consciously deal with using animals for food, for example, knowledge on the origin of the animals (e.g., if they were from a wild population or bred) is required. Quality labels are sometimes helpful, but insufficient verification and greenwashing promote mistrust, scepticism, confusion, and resentment towards green products [32]. Regarding the influence of values, Ateş stated that preservice science teachers, for example, may have a perceptual bias if they are vegetarian, even if they have enough knowledge about environmental issues [33]. Although agriculture conceptions have been well analysed (e.g., conceptions surrounding the intensive livestock farming of cows, pigs, and chickens) by different researchers (e.g., [34]), aquaculture conceptions have not been analysed. This raises a fundamental question: what knowledge and competencies do PSTs have to assess aquaculture products?

1.2. Aquaculture

What are aquacultures, and how can this topic be integrated into lessons? The term aquaculture refers to all living aquatic organisms (e.g., fish, mussels, crabs, and algae) in a controlled farming system [35]. The origin of this term dates back to the ancient Romans [36]. Fish farms account for almost half of all aquaculture farms [37,38]. Most products are produced in Asia, in countries such as China, whereas Europe only produces 11% of aquaculture products [39]. Fishpond cultivation is the biggest part of the aquaculture industry in Germany. Germans eat popular fishes such as herring, tuna, salmon, and trout. Not all species are common in aquacultures. The per capita consumption of such food in Germany is 14 kg, whereas the global per capita consumption is 20.6 kg [39]. Rapid growth, production efficiency, simple cultivation, tolerance for a high livestock density, and tolerance for low oxygen and water quality are the criteria used to breed species in aquaculture farms. The aim of aquaculture is to introduce new jobs and prevent the global safeguarding of food. Three types of aquacultures can be distinguished:

Offshore: This type of aquaculture is used in a limited area within a lake, river, or sea where aquatic organisms are locally isolated [40]. Other organisms may enter this area or escape. Dating back to the 1980s, the spread of the Pacific oyster Crassostrea gigas, for example, was unchecked in the North Sea. The reason for this was the cultivation close to the Island of Sylt [41]. This type of aquaculture does not exclude pathogen interactions between the organisms within the offshore area and outside of the mesh. However, by-catches can be avoided.

Raceways: This type of aquaculture involves a flow-through system (an artificial channel) enclosed with a ventilation system. A high livestock density is possible. Filtration is not used, and instead, the water is exchanged [35]. The advantage is that it does not require elaborate technology. However, food remains and metabolic products from the fish pollute the environment when they flow as unfiltered sewage into rivers and lakes.

Recycling systems: This type of aquaculture is a closed aquaculture system that includes aquatic organisms grown in separate tanks. A large production volume is possible, and these aquacultures do not harm the environment. This system allows the needs of the organism to be directly addressed (e.g., the use of antibiotics to tackle illnesses) without damaging other organisms. The manufacturing costs and use of energy-producing products are very high when removing fish from a wild population [42].

Aquaculture industries are highly important because the consumption of 180 tons of fish per year [39] cannot be supported by natural fish stocks worldwide. Nowadays, the cultivation of shellfish, crabs, algae, and fish represents half of all aquacultures [38]. Man-made habitats, however, are increasingly endangering endemic fauna, especially when natural habitats are destroyed for this purpose [43]. In some places, aquacultures are grown where water is scarce (e.g., sub-Saharan Africa, the Middle East, and North Africa) [37]. A high number of individuals can cause infections and parasite infestations [37,44]. Therefore, using antibiotics is very common. In a previous study, 400 pig, poultry, and fish farmers were interviewed. The farmers stated that they used up to 70% antibiotic prophylactics when the animals were not sick [45]. Another problem with aquacultures is that the animals have to be fed, which often requires the use of wild fish. Excrements and the food remaining from fish cause problems if they enter the environment in an uncontrolled way. The distribution of contaminants within the water column introduces contaminants into the food chain [46,47]. Additional problems exist in various production stages [38], which increasingly endanger the health of aquatic organisms within the food chain and the end consumer [48]. Despite all the negative arguments against aquacultures, some scholars have made some positive arguments about aquacultures. Froehlich et al. analysed 1.500 news headlines (published between 1984 and 2015) in developed and industrial countries. They reported a lack of the knowledge required to assess aquaculture quality [49]. Similar results were provided by Hynes et al. [50]. They identified that only four to one in five of the seven hundred Swedish participants knew about different aquaculture farms. Bacher described that end consumers have concerns in terms of the health and safety of breeding stocks [51]. Yi et al. identified the relationship between the environmental values of consumers and whether they purchase aquaculture products. Korean consumers were willing to spend more money on sustainable products when their attitudes towards environmental protection were higher than those of consumers with a lower environmental value [52].

However, fish is considered an important component of a balanced and healthy diet (due to its omega-3 fatty acids, minerals, and essential trace elements). The EU aims to expand the aquaculture industry so that it can become sustainable, and the sound knowledge of, opportunities for, and limitations of aquaculture products crucially influence end consumers’ choices. Supermarkets, brochures, and traders on weekly markets offer a wide range of aquaculture products, such as fish. Some of the products are created through sustainable production. Labels and quality marks are provided to guide the end consumer’s choice of goods. Bacher found that most customers had health concerns and issues with breeding processes that occur in aquaculture [51]. The industry is growing fast, which introduces both opportunities and risks. To assess the sustainable quality of aquaculture products, environmental literacy (EL) is necessary. EL was specifically established for environmental education and consists of four cornerstones: knowledge, attitudes and values, behaviour, and skills [53].

The topic of aquacultures is particularly relevant to the three pillars of ecology, economy, and social aspects, which are used to promote responsible consumption and production awareness. The decision to purchase animal products is connected with values (e.g., environmental protection and welfare) and the regional versus global consequences of physical aspects (e.g., enjoyment and the habits of long-standing procedures) [54,55], which lead to an increased field of advantage and conflicts (see

Table 1. Examples of SDGs in the context of aquaculture.

Context	SDG [3]	Potential and Conflict Area
social aspects:		(+) Healthy diet, number of potential jobs (e.g., larger companies), food security. (−) Low wages for competitive advantages, loss of small business (fisher).
economy:		(+) Provides new stable and nutritious sources, control of the breeding system (antibiotic against disease), and higher yields (e.g., [56]). (−) Pressure the world market economy.
ecology:		(+) Animal welfare and protection (e.g., biodiversity), no by-catches, fewer parasites. (−) Sewage from a closed recirculation system (e.g., [57,58]), antibiotics, livestock farming.

).

1.3. Research Goals

Based on the results of the discussed studies, we focused on five objectives:

• The content level, to monitor PSTs’ conceptions about aquacultures, sustainability, and environmental concerns when deciding whether to buy aquaculture products;
• Whether a semantic differential (SD) is an appropriate psychometric instrument to measure PSTs’ perceptions of aquacultures regarding interest and usefulness;
• Testing the environmental motive scale (EMS) [11] to determine an individual’s concern with aquacultures,
• Testing the inclusion of nature in self scale (INS) [59] to analyse the PSTs’ connectedness with nature,
• Testing a self-developed item set on system and consumption knowledge as well as the social influence of PSTs.

2. Materials and Methods

2.1. Structure of the Questionnaires

We used five open questions, three psychometric measurements, and a self-developed set of items to measure system and consumption knowledge and social influence.

2.1.1. Categorisation of Preservice Teachers’ (PSTs) Conceptions

The reconstruction of knowledge is individually based on a lifelong and accumulative process that involves personal experiences and scientific explanations [60,61]. For this study, the perceptions and feelings of individuals were differently characterised. After extracting the main categories and subcategories by applying the qualitative content analysis used by Mayring [62], we used five open questions (see

Table 2. Cohen’s kappa scores for inter- and intra-rater reliability.

Question	Cohen’s Kappa
	Intrarater Reliability	Inter-Rater Reliability
(a) How do PSTs perceive the term aquaculture?	1.00	1.00
(b) What are the reasons for using aquacultures according to PSTs?	0.76	0.51
(c) How do PSTs perceive the term sustainability?	0.61	0.17
(d) Which problems do PSTs see when buying aquaculture products?	0.70	0.82
(e) According to the PSTs, who will benefit from aquacultures and what are the benefits?	0.75	0.44

a–e). The inter-rater reliability score was determined by one researcher in the didactic biology group.

(a)

To determine the conceptions about aquacultures, we explored 21 subcategories from two main categories: ecology (which included fish, aquatic organisms, water, marine organisms, the ecosystem, plants, animals, algae, molluscs, crabs, aquafarming, plankton, and bacterial culture) and anthropocentric aspects (which included the food industry, controlled conditions, the economy, enclosed systems, mesh, cages, monocultures, commercials, and assigned stocks).

(b)

To determine the reasons for using aquacultures, we explored nineteen subcategories from five main categories: consumption (which included the food industry for consumers, fish consumption, and animal feed processing), breeding (which included breeding, the fish industry, livestock farming, and antibiotics), chance (which included alternative solutions to open land, breeding endangered species, sustainability, economic benefits, and research), plant organisms (which included plants and algae), and animal organisms (which included molluscs, fishes, crabs, marine animals, and animals).

(c)

To investigate perceptions about sustainability, we explored 32 subcategories from four main categories: ecology (which included animal welfare and the environment), the economy (which included recycling and the economy), social aspects (which included aspects of the next generation and fellow human beings), and environmental attitudes (which included protecting natural resources and being environmentally friendly) (for item examples, see

Table 3. Categorisation examples of teachers’ conceptions of sustainability.

Statements	Main Categories
	1	2	3	4
ID_160: An economy 3 that conserves natural resources 1 and has little impact on the environment 1.	1	0	1	0
ID_376: Sustainability is the consumption 3 and, production 3 of things and food 3 that will not harm 4 the environment 1 or the producers 2. It is thought to be a solution to environmental issues 4 for the environment’s 1, humans’ 1, and the climate’s sake 1.	1	1	1	1
ID_411: To act in a way 4 so that future generations 2 will not have disadvantages due to my actions 4.	0	1	0	1

Main categories: ¹ ecology, ² social aspects, ³ the economy, and ⁴ values.

).

(d)

To explore the open question concern with buying products from aquacultures, we inductively explored four categories and thirty-six subcategories: ecology (which included animal welfare, livestock farming, and conditions for breeding); the economy (which included the fulfilment of eco-labels and the quality of the fish); social aspects (which included hazards to human health and the pollution of resources”); and ecological problems (which included the anthropogenic pressure on the environment, antibiotics, and pathogens).

(e)

To determine the perception of who will benefit from aquacultures and what the benefits are, we explored fifteen subcategories from six main categories: growers (which included staying competitive, the control of stocks, and environmental protection); government authorities (which included complying with relevant laws and animal welfare, the preservation of natural resources such as wild fish, complying with hygiene standards, and promoting sustainability); economic (which included profit and quality); the consumer (which included low prices; quality, origin, label, enjoyment; and the protection of the wild population); and research.

2.1.2. Psychometric Measuring Instruments

Semantic differentials and seven scale points (−3 to +3) were used to analyse fourteen bipolar pairs by asking the following question: “I think aquaculture usage is…”. We aimed to monitor PSTs’ perceptions to identify their perceptions of the usefulness of and their interest in aquacultures. The antonyms were partially literature-based and partially author-selected.

The values and environmental concerns of the PSTs were analysed by exploring the response to the question: “Due to the environmental problems caused by aquacultures, I am concerned about the negative consequences of …”. Therefore, we added twelve items from the psychometric construct the environmental motive scale (EMS) [11] from the biospheric, egoistic, and altruistic categories and analysed the response by using a seven-point Likert scale, whereby “−3 = does not apply to the full extent” and “3 = apply to the full extent”.

With the scale for the inclusion of nature in self (INS, adapted from [59]), a seven-point Likert scale ranging from “A = very low” to “G = very strong” was used to describe the relationship between nature and the self, and two overlapping circles corresponding to nature and the self were drawn.

2.1.3. A Self-Developed Set of Items on System, Consumption Knowledge, and Social Influences

An individual fifteen-item set contains environmental competencies (system and consumption knowledge) and social influence issues relating to the topic of aquaculture. We used a four-point Likert scale to assess each question, whereby “1 = strongly disagree”, “2 = disagree”, “3 = agree” and “4 = totally agree”. For statistical analysis, we calculated the PSTs’ mean scores for each item first. Then, to analyse the classification categories, we used a factor analysis (see above).

2.2. Sample and Ethics Statement

We recruited 158 German university PSTs that had different profiles: (i) first subject: STEM (n = 47), humanities (n = 50), or social sciences (n = 32); (ii) second subject: STEM (n = 44), humanities (n = 56), or social sciences (n = 29). The median age was 24.8 (SD ± 4.5). In total, 46.3% of participants were females, 21.5% were males, and 32.2% did not specify, and they voluntarily completed the online questionnaire (with LimeSurvey) during the 2020–2021 winter semester. In total, 64 PSTs were registered in the bachelor’s programme and 62 were registered in the master’s programme. In total, 23 PSTs were only studying STEM, 22 were only studying humanities, and 12 were only studying social sciences. All the participants voluntarily decided to participate and accept the conditions. Underage participants required parental consent, whereas adult students decided to participate on their own. We provided them with some information, such as the fact that the questionnaire was anonymous, we would not share their data with third parties, and they could not be identified in any way. All the data privacy laws were respected. The gender, age, and study status of the participants were anonymously recorded. According to the general ethical and scientific standards for research with humans, our study met all required standards.

2.3. Statistical Analysis, Validity, and Reliability

For the present study, the lead author inductively categorised the open questions by following the procedure used by Mayring [62]. The three measuring instruments and the individual item sets were analysed using factor analysis, where factor loadings below 0.4 were left out. All the statistical tests were conducted using R (the R foundation for statistical computing for Windows; Version 4.0.2 for Windows; www.r-project.org (accessed on 15 February 2021)).

Categorisation of PST conceptions: Each main category was only coded once (one or several statements within the main category = one, no statements = zero) for each participant. To assess 789 statements, 15% of all the data were randomly selected after three months by the first author (inter-rater reliability = 0.76) and a second nonpartisan person (intrarater reliability = 0.59) to test the quality of the responses. Cohen’s kappa was almost perfectly above 0.75 and substantially above 0.60. The value of zero and a random correlation were assumed [63]. The resulting Cohen’s kappa scores indicated that overall, regarding the open questions, a high level of agreement existed between the raters except for the question involving the definition of sustainability (Table 2). The inter-rater reliability score was determined by one researcher in the didactic biology group.

Psychometric measuring instruments and a self-developed set of items: We examined the semantic differentials, values, and environmental concern [11] of each PST and the responses to the 15-item set on system, consumption knowledge, and social aspects by using a four-point Likert scale (“1 = do not agree” to “4 = fully agree”) by using a factor analysis with R, whereby we used the psych packages [64] and GPA rotation package [65], and then conducted a principal components analysis (PCA) and oblimin rotation. The sampling adequacy was assessed using the Kaiser-Meyer-Olkin (KMO) test (>0.6 indicates moderate adequacy, >0.7 indicates intermediate adequacy, >0.8 indicates good adequacy, and >0.9 indicates strong adequacy) [66]. For the INS, we calculated the mean scores to observe the overall relationship between nature and the PSTs’ self-perception.

3. Results

3.1. Conceptions

We inductively formed all the categories according to the answers to the five open questions (Table 2a–e):

(a)

A total of 132 preservice teachers (PST) responded to the question assessing how they perceive the term aquaculture. Most statements were assigned to the subcategories fish (n_statements = 63), aquatic organisms (n_statements = 43), and water (n_statements = 35). Fewer statements were assigned to the subcategories the ecosystem (n_statements = 19), food industry (n_statements = 14), and controlled conditions (n_statements = 12).

(b)

A total of 125 PSTs responded to the question assessing the reasons to use aquacultures. We assigned the most statements to the categories consumption (n_statements = 74), breeding (n_statements = 58), chance (n_statements = 45), plants (n_statements = 20), and animals (n_statements = 14).

(c)

A total of 98 PSTs replied to the question that asked how they define the term sustainability. We explored four main categories from the three pillars and added environmental attitudes (Figure 1), which resulted in a total of 32 subcategories. In terms of the main category of environmental attitudes, the PSTs’ responses mainly fell within five subcategories: protecting natural resources (n_statements = 45), the environment will not be damaged (n_statements = 27), the utilisation of resources (n_statements = 25), being environmentally friendly (n_statements = 25), and not wasting natural resources (n_statements = 15). The main category of ecology was predominantly referred to through the three subcategories of the environment (n_statements = 43), handling living beings (n_statements = 19), and the planet (n_statements = 15).

(d)

A total of 129 PSTs responded to the question, assessing which notions of concern they have when buying aquaculture products. In terms of the main category of ecology, regarding the PSTs that do not eat aquaculture products, most statements referenced animal welfare, housing conditions, and ethical concerns. Regarding the main category of ecological problems, the subcategories that were most frequently referenced were antibiotics and anthropocentric impacts on the environment. The main category of social aspects was referenced in a few statements; thus, the participants mentioned employment conditions and unlimited consumption, for example. A few statements on eco-labels and product quality were analysed within the main category of the economy (

Table 4. Notions of concern for aquaculture products.

Frequency of Eating Products from Aquaculture	Ecological Aspects	Economical Aspects	Social Aspects	Ecological Problems
Often (participant = 3)	2 statements	0 statements	0 statements	1 statement
Sometimes (participant = 30)	19 statements 63.33%	4 statements 13.33%	5 statements 16.67%	17 statements 56.67%
Seldom (participant = 43)	33 statements 76.74%	4 statements 9.30%	7 statements 16.28%	29 statements 67.44%
Never (participant = 53)	37 statements 69.81%	2 statements 3.77%	15 statements 28.30%	25 statements 47.17%

). The statements trended towards mentioning ecological aspects and ecological problems, regardless of how often the PSTs ate aquaculture products.

(e)

A total of 93 PST responded to the question, who will benefit from aquacultures and what are the benefits. Most participants referenced the main category of growers, whereby they referenced staying competitive (n_statements = 45). Participants also referenced the main category of government authorities and two subcategories most frequently, namely complying with relevant laws and animal welfare (n_statements = 15 each). The PSTs reference the main category economic alongside profit (n_statements = 27). The end consumer as a main category was not often mentioned. Most of the PSTs mentioned a low price. Some of the PSTs associated this question with research (n_statements = 10), but nobody mentioned politics in their statement.

Comparing the responses of women and men showed that their conceptions regarding the five questions were not significantly different between them.

3.2. Factor Analyses of Semantic Differential (SD) Regarding the Uses of Aquaculture Perception

The result of a principal component analysis (PCA) on 14 SD adjective pairs revealed two separate factor structures for usefulness (M_average = −0.62, SD ± 1.62) and interest (M_average = 0.38, SD ± 0.38) (Figure 2).

The Kaiser-Meyer-Olkin measure (KMO) [66] of sampling adequacy (0.9) was very strong for this factor analysis (

Table 5. SD factor scores of PCA analysis with oblimin rotation.

Item	Usefulness	Interest
(SD09) terrible|beautiful	0.89
(SD15) awful|lovely	0.87
(SD08) valueless|valuable	0.86
(SD14) unsustainable|sustainable	0.80
(SD02) threatening|harmless	0.78
(SD06) dangerous|safe	0.76
(SD13) risky|reliable	0.75
(SD10) dispensable|indispensable	0.72
(SD01] useless|valuable	0.71
(SD12) unnecessary|necessary	0.68
(SD11) uninteresting|interesting		0.86
(SD03) boring|exiting		0.82
(SD07) insignificant|meaningful		0.62
(SD04) monotonous|diverse		0.52

N = 148 PSTs.

), and the Bartlett-test of sphericity was significant (p < 0.001). The table shows two separate factors that had a high factor score. Cronbach’s alpha was 0.94 for usefulness (n_items = 10) and 0.80 for interest (n_items = 4), which were very high. Men are slightly more interested and saw aquacultures as being slightly more useful than women.

3.3. Analyses of Values and Environmental Concerns

A PCA on twelve items regarding the environmental concern with aquacultures resulted in three subcategories (Figure 3): biospheric (M_females = 1.51, M_males = 0.79), egoistic (M_females = 0.03, M_males = −0.44), and altruistic (M_females = 0.78, M_males = 0.15). Cronbach’s alpha was 0.89 for biospheric, 0.80 for egoistic, and 0.87 for altruistic, which were very high. The Kaiser-Meyer-Olkin measure (KMO) of sampling adequacy (0.86) was very high for the factor analysis, and the Bartlett test of sphericity was significant (p < 0.001).

3.4. Inclusion of Nature in Self (INS)

Our comparison of the INS scores revealed a mean score of 4.77 ± 1.28 after assessing the PSTs’ cognitive beliefs and detecting their connectedness with nature (Figure 4A,B). The relationship between nature and the self for this target group was very high. No differences exist between women and men.

3.5. Analyses of Preservice Teachers’ Competencies and Social Influence

A PCA on the individual item set (n = 8) yielded two factors: consumption knowledge (M_{mean PST} = 1.71) and social influence (M_{mean PST} = 3.08). The Kaiser-Meyer-Olkin (KMO) [66] values for both factors were 0.81 and were thus acceptable for the factor analysis (

Table 6. Consumption knowledge and social influence factor scores obtained from PCA analysis with obliminal rotations.

Item	Consumption Knowledge	Social Influences
1. Stocks from aquaculture do not harm local species because they are within a mesh.	0.78
2. Feed remains and excretions from fish from open aquacultures do not harm the environment because they are diluted in the ocean.	0.48
3. I regularly share information about sustainable products with my friends.		0.82
4. I discuss the consequences of conventional products that cause environmental problems with my friends.		0.75
5. I speak with my parents about the advantages and disadvantages of conventional and sustainable products.		0.73
6. When I go shopping with my friends or parents, we buy sustainable products.		0.66
7. I consider the packaging information (e.g., the origin of the fish) in my purchase decision.		0.66
8. I would be willing to pay more for sustainable products.		0.62

N = 134 PSTs.

).

Based on the low factor scores, the items on system and consumption knowledge were excluded (

Table 7. System knowledge (items 9–13) and consumption knowledge (items 14–15).

Item	Disagree	Rather not Agree	Agree	Fully Agree	M/SD
9. I prefer to avoid buying sustainable products if they come from overseas. (R)	25	57	42	10	2.72 0.85
10. Products from aquacultures are redundant because we have a plethora of other products. (R)	38	61	24	11	2.94 0.89
11. Wild fish are healthier because aquaculture fish contain more antibiotics and other pollutants.	12	42	68	12	2.40 0.77
12. Breeding each fish in an aquaculture.	58	62	12	2	1.96 0.70
13. I have elected not to buy sustainable foods when they originate from overseas. (R)	25	57	42	10	2.72 0.85
14. Aquacultures reduce overfishing in the oceans. (R)	16	33	63	22	2.33 0.88
15. The use of antibiotics damages the environment only in the closer surroundings of open aquacultures.	60	40	11	23	1.96 0.74

(R) reversed item; N = 134 PSTs.

).

Further studies are necessary to determine if these items are correctly understood. For this target group, the measuring instrument was not a valuable instrument (items 9–15). No significant differences existed between women and men.

4. Discussion

Our consumption of aquatic organisms (e.g., fish) continues to increase rapidly [39] and cannot be supported by natural livestock. Our overconsumption of natural resources forces us to rethink sustainable consumption and the production methods that support sustainability. Our major goal with this study was to explore how preservice teachers (PTSs) conceptualise and value aquacultures, which is a less familiar topic.

The overall perceptions that PSTs had about aquacultures related to a range of scientific concepts about the term aquaculture, but their reasons why different stakeholders use aquacultures were not accurate. In particular, politicians were not mentioned. The belief that using aquaculture products reduces overfishing in the sea was predominantly mentioned, although some PSTs did not mention this (see Table 7, item 14). Aquacultures were predominantly negatively perceived. Health aspects were not specified. Mazur and Curtis conducted a literature review, stakeholder interviews, and a survey that was mailed to the public on aquacultures as a part of two regional case studies in Australia. Participants likewise mentioned more disadvantages than advantages with aquacultures, but there was uncertainty regarding the environmental hazards caused by aquacultures [67].

The social pillar contains the weakest category next to ecology and the economy [68,69,70]. This trend was demonstrated in our study as well. Walshe conducted concept mapping (n = 27) and semistructured interviews (n = 26) with adolescents on their definition of the term sustainability within a case study framework. The wide variety of understandings of sustainability aligned with the results of our study. In addition to exploring how adolescents perceive the term and purpose of sustainability, he also determined the timescale for sustainability with his study (Figure 1) [71]. However, the concept of sustainability indicates a key concern regarding survival on this planet and the economic and social consequences that affect us now [3,29]. Maurer and Bogner stated that freshmen (n = 464) perceived humans as the greatest environmental threat [72]. In our study, PSTs were willing to pay more for sustainable products, which aligned with the results of a study by Yi [52], but not when the products came from overseas (see Table 7, item 8).

The earliest sustainability movements triggered the publication of Carlowitz’s book Sylvicultura Oeconomica, in which he claimed that individuals should only take as many resources, e.g., wood, that can grow back. Regarding the question of who will benefit from aquacultures and what the benefits are, the PSTs saw the capitalist production methods and low cost for industry and customers rather negatively. This belief was clear and consistent, but each of the participants had diverse views on the role that they play and which issues need to be prioritised [73]. The concern with buying aquaculture products was assessed with statements such as “same like buying meat from mass livestock farming: pollution of antibiotics and animal welfare” (ID_70: female, 24, academic subjects: biology and chemistry) or “production of aquaculture products may endanger animal welfare and environmental protection. They can also be health endangering” (ID_221: female, 24, academic subjects: German studies and politics), for example. In conclusion, the PSTs were concerned about aquacultures in terms of the animals and health. Moreover, we explored the values of the PSTs with the question “environmental problems caused by aquacultures, I am concerned about negative consequences for…”, but the sentence was either contradictory or the PSTs did not understand the content of the question. The score of the latent variable biospheric was higher than egoistic and altruistic, but on average, the PSTs did not see the environment as endangered. The PSTs indicated that they do not eat aquaculture products very often, so perhaps they are uninterested in aquacultures and perceive them as more useless. However, transferring knowledge is important to assess lesser-known topics. In the context of a school, PSTs must be able to support their ethical judgement about consumption practise to increase their sustainable and responsible decisions concerning food. Only the overall knowledge of an individual’s conceptions about sustainability, consumption possibilities, and environmental competencies contributes to the preconditions that lead to success in pursuing different consumption possibilities. Agriculture teaching material, which supports decision-making processes in school as well as in university, is missing. In this regard, Seixas et al. see e-learning as a rapid and efficient method that can be used to teach individuals about aquacultures [74]. Wingenbach et al. emphasised that those organizing aquaculture education programmes are not aware of or do not care about educational benefits. They encourage collaborations between high school teachers and/or school districts when enrolling individuals in aquaculture education outreach programmes [75]. According to the results of a study by Conroy et al., aquaculture topics are not often taught in schools. Only 23.6% of 406 respondents indicated an interest in teaching aquacultures, but 300 teachers thought that teaching students about aquacultures was more useful than teaching students about other agricultural content areas. The cross-curricular integration of experiential science and mathematics was proposed in [76]. Regarding green genetic engineering, Alfs et al. [77] highlighted that new nutrition sources are disliked by consumers. Enjoyment and taste are important for consumers. Unlike green genetic engineering, aquacultures are not new. However, the trend towards eating animal products has declined in younger generations. However, discussing such topics in classrooms is important.

Limitation

This study was conducted during the COVID-19 pandemic by using the platform LimeSurvey when the university was closed. The respondents were contacted via a mailing list and were not participating in a lesson. Less than 10% of the invited individuals participated (n > 400 mouse clicks), and two out of every three participants cancelled the questionnaire after a few questions. One-third of all participants studied biology as their first or second subject. The open questions were an appropriate method to collect data on individual conceptions; however, no control relating to time or limiting the use of other websites to answer the questionnaire existed. The sample represents preservice teachers from one German university, which means the results cannot be generalised.

5. Conclusions and Directions for Future Research

The 2021 and 2030 agendas encourage leaders of education institutions to implement education on sustainable development in their curricula. Since the 1970s, individuals have made a large effort to integrate environmental education (EE) into science teaching worldwide. Sustainable development goal number 4, education, encompasses inclusive and equitable quality education and promotes lifelong learning opportunities for all [3]. Preservice teachers (PSTs) must be able to reflect on their actions before they support students’ value development. The use of scientific knowledge content (1), the application of epistemological and methodological knowledge (2), judgements (3), and science communication (4) are the four main competences that are developed in natural science classes [78]. Learning about aquacultures can foster these competencies; therefore, aquacultures are an ideal topic for the field of education for sustainable development education [29], as they cover the three pillars of ecology, economy, and social aspects, which are used to promote responsible consumption and production awareness (see Table 1). This topic could also be integrated in the humanities (e.g., by analysing the text of an ESD issue) or the social sciences (in terms of politics and the impact of sustainable nutrition), as issues regarding sustainable development education have to be embedded in the Lower Saxonian curriculum for two years (ESD degree, German: BNE Erlass). Knowledge transfer regarding the use of and interest in aquacultures was not observed in our study. However, ecological problems were perceived. We propose an empirical research intervention in an outreach lab for students. Furthermore, PSTs can enhance their own skills by teaching students how to implement their values, knowledge, and environmental concerns when making purchasing decisions.

Teaching-learning settings in school: Next, according to the results of our study, an inquiry-based learning approach offers an overview of the value of aquacultures for students and PSTs. Hands-on experiments would cover the four main competencies: (1–2) Experiments with fish fingers is one way to determine what kind of species a fish is and its origin (e.g., wild or from aquacultures, as determined by searching the labels on the package), and experiments on the salinity of water or the distributions of fish excretions and food within a water column are examples of experiments that can be conducted to explore abiotic factors. One central aim is to encourage learners’ competence when assessing ethical questions. Animal welfare and environmental influences on different aquaculture farms are some examples that can be discussed (3). Moreover, communication (e.g., social forms and the documented representation of the structure and process of results) is important to help students make decisions as future consumers (4). Aquacultures illustrate a dilemma where various interest groups play a role (such as breeders, consumers, and politicians), and a simulation game could also be used. Future workshops and legal proceedings are other ways that the unit could occur in school or in an outreach laboratory.

Teaching-learning settings at universities: The topic of aquacultures can be implemented in a didactic biology lecture. The use of the knowledge in this scientific content should be determined by the students themselves in groups based on the concepts of aquafarming and sustainability. After presenting their results, the following questions could be discussed: (i) What kinds of social groups are affected by aquafarming? (ii) What information is required for these social groups? (iii) Which social groups have to act to enact sustainable aquafarming? We discussed these questions during a biology lecture for two different courses. The results showed the complexity of the topic in terms of both the advantages and disadvantages of aquaculture. Unlike what occurred during our study, key nutritional aspects were considered. Politicians have a responsibility to society that was not mentioned in our study. Due to the relatively small sample size, analysing qualitative content such as interview (single or group) responses is recommended for future research. By including this, the impact of environmental literacy and the assessment of aquaculture products can be demonstrated, which may finally raise environmental awareness.