TS4 – Fisheries Oceanography

On Thursday, we conducted fish trawls at stations 3 and 4 – the deepest trawl stations. All trawls went smoothly, however, we did break the trawl net foot rope at station 4! fortunately, the excellent crew of the RV Hatteras was able to mend the net and get it back in working condition. Stations 3 and 4 are very exciting for fish trawling because we have the opportunity to capture unique deep-sea fishes. At station 3, we captured the highest overall catch and diversity (>20 species) of the cruise. Most species were reef-dependent, indicating patches of deep-water reefs at this station. At station 4, we caught some very cool deep-water species! Dr. McLean was particularly excited about the Spotfin Dragonet (Synchiropus agassizii), Fawn Cusk Eel (Lepophidium profundorum), and Shortnose Greeneye (Chlorophthalmus agassizi). Pictures courtesy of the Smithsonian Tropical Research Institute are shown below. Several unique specimens were collected for the UNCW Ichthyology teaching collection, while others were taken for stoichiometry analyses. We conducted nearshore trawls at stations 1 and 2 on the final working day. Catches were low and made-up of common coastal/estuarine species such as Pinfish (Lagodon rhomboides), Atlantic Bumper (Chloroscombrus chrysurus), and Striped Anchovy (Anchoa hepsetus). Low catches were not surprising as many coastal fishes migrate offshore prior to winter. Although we have only completed four cruises, we are already noticing a trend – the shallow, nearshore sites are showing pronounced seasonality, while the stable, deep sites have had similar catches in all seasons, highlighting the contrast between coastal and deep-sea ecosystems.

Spotfin Dragonet