Midwater Trawl - Seine Comparisons
Objectives:
The objective was to collect young-of-the-year, juvenile menhaden in a midwater trawl and a seine from two Chesapeake Bay tributaries (Patuxent River, Choptank River) to estimate relative abundances, ages, hatch dates, and growth rates. A coordinated trawling and seining effort was synchronized and conducted so that each trawl site was paired with a close by, nearshore seining site. Collections of menhaden will be compared to determine if catch levels are correlated and if menhaden of different sizes, ages, and hatchdates are represented in the catches of the trawl (offshore) and seine (nearshore).
YOY Atlantic Menhaden and Other Fishes:
The 18-m2 mouth-opening, midwater trawl with 4- mm meshes in the codend was deployed from RV Carson at each site. Deployments were of 20- min duration, with the net fishing the water column in 2-min steps from surface to bottom. On nearby seinable beaches, a 100-ft bag seine with ¼” mesh was deployed in a quarter-sweep from shore. Catches of YOY menhaden are summarized in Tables 1 and 2. Up to 30 menhaden, bay anchovy and alosines were measured from each trawl and seine sample. Samples or subsamples of menhaden were preserved in ethanol and brought to CBL for otolith-aging and hatch-date analysis. Species and numbers of other fishes in trawl and seine catches were recorded.
Table 1. MEN12-03, 7-8 August 2012. RV Rachel Carson, summary of midwater trawl catches and mean lengths of young-of-the-year menhaden by system and station.
Table 2. MEN12-03, 7-8 August 2012. Seine sampling summary of catches and mean lengths of young-of-the-year menhaden by system and station.
