PROGRESS SERIES Prog. Ser. Laboratory. Woods Hole. Massachusetts - PDF document

PROGRESS SERIES Prog. Ser. Laboratory. Woods Hole. Massachusetts plankton grazers. From 1988 samples were the southern with a through a Collection stations in the Gulf of the southern shallow waters central shoal and deeper waters along the southern mesh net tered onto size ca 1.2 filtered with mesh net, then washed Large phytoplankton These net samples a dissecting pumping large mesh net. Retained material then screened again samples were collected with bottom-to- using 128 in length (larval fish, chaetognaths, amphipods, zooplankton samples before analysis. exception occurred then analyzed. trap materials southern margin et al. samples had preserved with sodium azide moored traps, frozen until analysis. comparison with the Georges results, POM offshore bloom diatoms in North Atlantic April to in the area bounded 57' N, during inshore upwelling To obtain species cultures, natural surface nutrient concentrations to 7.5-8.3 7.5-8.3 (aq)] concentrations in cultures. resulting nutrient-enriched unfiltered with natural phytoplankton 8 d board ship a dock relatively small algal growth occurred and algae by natural at 1 2 d (Parsons et al. with 100 phytoplankton species these closed-system experiments last 2 last 2 samples because they best new growth and were by POM in inocula. Rearranging equations containing 1 acid, dried without rinsing using a stainless steel pestle (Wig-L-Bug). Powdered sealed in evacuated to slowly over 4 mass estimated calibrated electronic manometer. Mass balance Zooplankton, phytoplankton, with 1 60 "C extract containing Dissolved inorganic carbon: polyethylene bottles, the dark. from DIC 251 or S isotope mass spectrometers. were made tank gases against interna- reported relative isotopic compositions in air carried through these usually differed POM, zooplankton Samples that negative (higher) samples that with more negative (lower) analyses were performed with (1981). Uncertainties given confidence intervals. isotopic compositions Georges Bank, stations did not diatom production pronounced in central shoals 7 POM central shoals region regions occurred late summer bloom, POM over shoals region enriched in vs samples vs -24.0 Georges Bank. Six DIC enriched in Maine samples net phytoplankton sampling (no were again late March sample had value. This waters along southern margin the other samples collected in net samples the central shoals region the northeast shoals. Chlorophyll sp. did dominate the bulk POM in these areas, 2). Other 3), and Coscinodiscus sp. in may also been suggested a possible in phytoplankton (Descolas-Gros Guy et shown that rapid accompanying increases nate uptake generally account tributions in remains somewhat specula- tive, a growth-rate-based model studies show that especially in Antarctic waters (Sackett 1965, Rau al. 1987). not inconsistent a model that states that rate, since Antarctic diatoms photosynthetic carbon (Fischer 1989). Higher growth rates Bank diatoms could explain their Antarctic diatoms could also synthesis in 1980). However, phytoplankton after suggesting that not solely storage. Measuring isotopic compositions fucoxanthin, a common diatom pigment, may helpful in future studies contributions to food diatoms most often analyses, evidence 4) indicates ecosystems. A most closely present study). Occurrence growing diatoms other slower-growing productive part the year plankton (Fig. 6) central Georges Bank alternative source Georges Bank Maine. This primary productivity is 270 g C Georges Bank, rather than in this system diatom contributions plankton diets zooplankton feeding a system other, slower-growing plankton values in this bloom to August.) Given fast-growing diatoms zooplankton growth in the Bank (estimated the nearby estimated importance is 20 given zooplankton note that highly sensitive probably minimum because the end-member value