Fisheries Monitoring

Fisheries Monitoring

In order to capture how the restoration is benefiting Shinnecock Bay as a whole, we monitor broader elements of the ecosystem, including biodiversity.

How do we measure biodiversity?

We use standardized fisheries surveys, underwater video, and eDNA (environmental DNA).

Most marine fish are sensitive to water quality and become stressed during eutrophic or harmful algal bloom conditions, sometimes even experiencing mass mortality (e.g. fish kills). In addition, fish and invertebrates rely upon healthy and dense eelgrass habitat for food, habitat, and cover from predators. If water quality, habitat, and other environmental conditions are unfavorable, it can impact biodiversity in the bay.

Because fish can represent a good indication of how the ecosystem is doing, long term monitoring of these populations can tell us if the bay is recovering.

Surveys provide us with standardized and consistent information on the range of biodiversity in the bay, and the size, abundance, and local distribution of the various species we catch. We have used a trawl survey for all twelve years, BRUV surveys from 2014-2019, and eDNA from 2019 to the present.

Individually and collectively, these monitoring surveys can identify common or “resident” species and reveal how the composition of marine life in the bay changes over seasons or years. By cross-referencing biodiversity data with temperature and water quality, we can also infer how life in the bay may be impacted by environmental factors.

The long term fisheries monitoring work in Shinnecock Bay will help document how our ShiRP restoration efforts over the last decade have had transformative benefits to the wider bay ecosystem.

Methodologies

Our longest running survey method, now in its thirteenth year, involves trawling with a small net towed behind our research vessel for several minutes at different sampling stations around the bay. Our staff and volunteers quickly identify, measure, and release organisms back into the water, documenting catch in various bay locations, habitats, and seasons.

Trawl Surveys

Bait attached to PVC pole

Rope and Buoy

GoPro

BRUVs

For several years, we used Baited Remote Underwater Videos (BRUVs). These are submersible HD video cameras anchored to the bottom of the bay, and placed in front of a bait bag that attracts nearby marine life. After resting on the bottom for at least an hour, the cameras are retrieved and the videos are downloaded and processed. Trained students and volunteers review the footage in the lab and identify species recorded on video.

What are BRUVs?

Baited Remote Underwater Videos (or BRUVs) are utilized around the world as a non-invasive method to sample fisheries and observe behaviour without direct contact with species.

We began using Environmental DNA, or eDNA, as an additional survey technique in 2019. eDNA allows us to obtain a “biodiversity snapshot” of a particular area by collecting and processing a water sample. We have taken eDNA samples alongside in parallel with trawl tow, so that the two methods can be directly compared.

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Fisheries Monitoring