Impact of microplastic pollution on juvenile survival and growth of commercially important fish species in different coastal ecosystems
The ecological challenges of microplastic (MP) pollution may be considered as one of the most urgent anthropogenic issues which needs to be addressed and understood to maintain and preserve biodiversity. As MP research has been conducted mainly on quantification and chemical characterization, holistic approaches aiming at the investigation of MP effects on a smaller scale are needed to truly assess the potential detrimental effects. As the implications may vary between species and life stage, conducting more in-depth studies is considered crucial both from a scientific and a social perspective. Taking the vital biological, social and economic value of coastal ecosystems into account, only multidisciplinary research will offer the insights needed to successfully accomplish future tasks such as ecosystem based management, sustainable usage of resources and also effective conservation and protection.
The research project will shed light on the ecological and socio-economic consequences of increasing MP pollution in coastal ecosystems. The central scientific question is thus:
What are the physiological and ecological implications of microplastic uptake by early life stages of fish in coastal ecosystems such as lagoons and estuaries?
The main objective is to evaluate the impact of MP on the growth, development and survival of juvenile fish of commercially important species and the potential consequences for recruitment and population dynamics of coastal fish stocks, in relation to different habitat quality parameters. As model organisms, representatives of the family Sparidae (engl.: seabreams; dt.: Meerbrassen), which are of commercial importance in many coastal regions, and are distributed widely in the temperate and tropical Atlantic (Hanel & Tsigenopoulos, 2011) will be selected. Largely carnivorous, they are expected to ingest micro-plastics of a wide variety and size range. Species of this chiefly marine family of bottom-dwelling fish frequently use nearshore habitats as nursery grounds (Abecasis et al., 2009; Ribeiro et al., 2006) and juveniles are known to show a high site fidelity (Erzini et al., 2002), therefore allowing population dynamics to be studied at different locations within a lagoon and estuary. Two to three of the most abundant seabream species at each site will be studied.
With this proposed project, a high level of multidisciplinarity is achieved by combining an array of methods (in situ studies, experiments and laboratory analysis) originating from different natural sciences on the one hand (e.g. fisheries ecology, chemistry, microbiology) and by integrating natural sciences with social and economic sciences on the other hand. The research will provide fundamental knowledge on evaluating the impact of one of the most severe human-induced ecosystem threats, namely habitat degradation and pollution, on one of the most valuable living resources for human use: fish. By focusing on early life stages of commercially important fish stocks which are known to depend heavily on estuaries and lagoons as breeding and nursery grounds, this study will help to further understand fish-habitat interactions as well as the effect of habitat quality parameters and pollution on the development and survival of juvenile fish and on their recruitment. Early life stages are known to be the bottle neck in development of fish populations (Cushing, 1996), hence scientific research on factors adversely affecting juvenile development and survival is considered crucial for the sustenance of fish stocks and coastal artisanal fisheries.
It is expected get a deep understanding of the spatial and temporal variation in habitat quality parameters as well as their impact on growth and development of commercially important fish stocks. Results from the project are suggested to be complemented with future monitoring programs to further study local trends in habitat quality parameters and fish stocks. Applying a high level of transparency (participation in workshops and conferences, joint bilateral and multilateral research, sharing of data), communication and presentation of results in a comprehensible way to all relevant stakeholders will increase the awareness of marine pollution and the comprehension of ecosystem functioning in science and society.