This is an old revision of the document!
Table of Contents
Group 10
<html><font size=6 face=“Arial”> Of Plastic and Plankton Got to find a better name</font></html>
Wiki site of the practical exercise of the IX Southern-Summer School on Mathematical Biology.
Here you will find the exercise assignment and the group's products.
If you are a group member login to edit this page, create new pages from it, and upload files.
Introduction
Many marine fish begin their life at ocean surface, where it lives for days to weeks, feeding mainly from zooplankton until its development is complete. The availability of such resource is therefore fundamental for these marine fish species survival.
Surface slicks are meandering lines of convergence on the ocean surface, usually formed by wind and internal waves, that accumulate zooplankton and other microorganisms, becoming an attractive spot for larval fish to feed when compared with other ocean surface areas. As the distance between surface slicks are of the order of 1 kilometer, larger larval fish, with increased swimming competency, are able to migrate to surface slicks in order to capitalize on concentrated prey resources, whilst other less competent small fish are simply dragged along. The mean size of fishes in slicks was found to be almost 30% larger than in other surface areas, showing the importance of these regions for fish development
However, these surface slicks also tend to accumulate micro plastics that are often mistaken as food by larval fish. Slicks contain a 7:1 ratio of plastics:resource, which is much larger than the ratio of 1:2 found in other surface areas. Consuming plastics may have multiple negative effects in fish growth, posing a threat to some species as its main nurseries become plastic deposits.
Assignment
Build a mathematical model for the fish population, incorporating the effects of resource and plastic accumulation in slicks and also the possible harmful effects plastics may cause in fish population.
Questions & Suggestions
We suggest you to focus on larger larval fishes, as they can actively search, or not, for slicks. I think it would be instructive to point the readers out to model the ones that are able to choose whether to be or not to be in slicks, since this is the behavioral aspect of the problem
Could larval fish maintain the plastic levels in surface slicks under control due to it misled consumption?
Could fish adapt to avoid surface slicks due to plastic accumulation? Would it make surface slicks a refuge for zooplankton? If so, could it be reversed once the ratio of plastics to zooplankton become small?
References
J.M. Gove et al. Prey-size plastics are invading larval fish nurseries, PNAS, 2019, https://www.pnas.org/content/pnas/116/48/24143.full.pdf