Hurricanes and Fish (Atlantic 29 Sept 2023)

Tropical Storm Philippe (AL17) and Tropical Storm Rina (AL18) are churning 😛 east of the Leeward islands. They are only 500 nautical miles apart and appear to be interacting, so the forecast is a bit uncertain. Here are the NHC forecasts as depicted by my TAOS/TC model …

click to embiggen.

However, the scenarios are still if either (especially Philippe) moves towards the islands, the environment is unfavorable and it will weaken; if it goes north as anticipated (can’t say expected at this point), it should get a bit stronger. As is typical in the patriarchy, Philippe will gain at Rina’s expense and will weaken, and that is what NHC is forecasting. So no real threats to land at this point, and not likely to be in the future.

Yeah, yeah, you’re thinking. No major impacts for humans. But what about the fish? There has been a lot of research about the impact of landfalling tropical cyclones on coastal fisheries as well as marine mammals. Changes in salinity, turbidity (water clarity), and so forth can be catastrophic and cause fish kills (link to NOAA article). Marine mammals can become swept inland trapped in ponds and other low lying areas and need rescue (link to another article, with advice on what to do if you find one).

What about deep water fish and mammals? There has been relatively little research on the subject. One very interesting study was of Demeral fish (bottom dwellers, like flounder) was done off the Outer Banks (link to NCSU article, and here is the original study in nature). Not exactly “deep” (120 feet), but far enough offshore to avoid stronger currents and the salinity and turbidity changes seen nearer to shore. Those fish mostly just migrated to deeper water. It makes sense that most deep water fish would not care too much about hurricanes other than waves.

I can’t find it at the moment, but I remember seeing a paper that tracked geotagged Atlantic Bottlenose Dolphins, and for the most part they got out of the way of incoming storms. The few that guessed wrong or stayed in the path were the ones that got in to trouble.

So that’s what seems to be what the impacts of storms are on fish. Tropical cyclones are an important part of Earth’s ecosystems. The have adverse impacts, but also are vital for transporting energy from the equator to the poles. They also stir up deep water nutrients, reshuffle coastlines both creating and removing debris, and have other secondary and tertiary impacts. As I often say, there are really no natural disasters, only natural events that have adverse impacts because we didn’t properly plan for them. Fish can’t plan for them. Humans can. Well, at least they should 🙁

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