| Objectives: Use otter trawls (if available), beam trawls (if not), Naturalist Dredge,
SEABOSS photography/bottom grab equipment, CTDs, and large (10-30 liter) Niskin water
bottles and ship?s ADCP to conduct the following operations: 1) determine changes
in distribution and condition of invasive colonial tunicate Didemnum vexillum on northern
Georges Bank gravel habitat, and also northeast of Great South Channel; 2) document
the influence other ecosystem components, substrates, hydrology, and disturbances,
including fishing disturbances on tunicate-benthic/demersal stock interactions; 3)
collect tunicate specimens for further study including DNA analysis, and collect near-bottom
water samples in tunicate areas; 4) explore the function of a newly-discovered benthic/demersal
community not influenced by trawling or tunicate colonization, 5) continue monitoring
recovery and productivity of untrawled gravel habitats in HAPC on northeastern Georges
Bank, as compared to nearby trawled habitats; also, time permitting, and 6) re-occupy
existing stations and sample new stations on a transect from the northeast corner
of NLCA to outside the eastern boundary of NLCA. |