Is there a trend between a fish’s total length and the way they use their habitat?

Goal: Understand if there is a trend between a fish’s total length and the way they use their habitat.

For my first data project, I gave myself the task of generally assessing if there is any trend between fish total length and habitat utility. Carbon (or delta 13C) traced habitat use with higher values suggesting seagrass habitat use and lower values suggesting mangrove habitat use. Nitrogen (delta 15N) traced how far up or down a particular animal is positioned in the food chain (e.g. top value = top position in food chain). By combining them together, you get an estimate of an animal's niche in the ecosystem with wide niches indicating a general diet and a narrow niche indicating a specialized diet.

Methods Used

Analyzed using regression and isotopic niche analysis and presented using scatter plots with a best-fitting line.

Results

• There is a general trend where fish transition from mangrove to seagrass habitats as they get larger.

From these analyses, I concluded that there is a general trend where fish transition from mangrove to seagrass habitats as they get larger. Additionally, the niche area did not change much between different size bins but there was a shift away from mangrove signatures with increasing body size. These analyses ultimately served as the basis for my first publication where I modelled the probability of mangrove, seagrass, and pelagic habitat use as fish grow. Results were reported back to fishers/stakeholders in Tanzania to further emphasize the importance of conserving coastal habitats when possible.

Note: This scientific poster won 2nd Best Presentation at the 2017 Coastal & Estuarine Research Foundation Conference.

If you want to see the above graphs in greater detail, please click below to open the presentation’s pdf in a new tab.