The Atlantic sturgeon, which is one of the world’s oldest species of fish, can live up to 60 years, reaching a length of of 15 feet (4.6 meters) and a weight of over 800 pounds (360 kg). It’s also endangered, due to past overfishing for its caviar. In order to protect the sturgeon that are left, it’s important to keep fishermen from catching them accidentally. That’s why researchers at the University of Delaware and Delaware State University are calling upon satellites, and an underwater robot known as OTIS.
In previous years, scientists had tracked the migrational routes of tagged sturgeons off the mid-Atlantic coast. In the current study, the researchers have cross-referenced those locations with satellite data from those same years, which includes the water temperature and chlorophyll levels in those places. A pattern has emerged, suggesting that the fish were moving to stay with pockets of water where those factors were more to their liking.
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Now, it is hoped that by identifying those sturgeon-friendly temperatures and chlorophyll levels on current satellite data, it will be possible to warn fishermen to temporarily stay away from those areas. Before such a predictive system can be put into operation, however, it has to be confirmed that it really is accurate. That’s where the oceanographic telemetry identification sensor (OTIS) glider comes into play.
As part of a 3-month mission that’s currently in progress, the torpedo-shaped robot is traveling by remote control to areas where the oceanographic satellite data suggests that sturgeon will be present, to see if they are in fact there. OTIS is also able to measure salinity, dissolved oxygen levels, chlorophyll and currents, plus it can detect tracking tags previously attached to individual fish.
So far, after three weeks, it’s found 10 Atlantic sturgeons. The same University of Delaware lab, headed by Prof. Matthew Oliver, previously had success using OTIS to establish a link between specific water conditions and the presence of tiger sharks.
Down the road, Oliver hopes to have multiple OTIS gliders searching for sturgeon in different candidate regions at the same time.
Source: University of DelawareView gallery - 6 images