Modeling of climate forcing on a cold-ocean ecosystem, Conception Bay, Newfoundland

Abstract

Climate forcing of marine ecosystems has been the subject of increased research over the last few decades. We have developed a prognostic, 1-dimensional (1D) physical-biological model to study climate forcing of cold-ocean ecosystems. The physical model is based on the MellorYamada level 2.5 turbulence closure scheme and is explicitly driven by meteorological data. The biological model consists of 10 state variables which include the mesoplankton and the microbial food webs. The model was applied to Conception Bay, Newfoundland, Canada with meteorological, physical and biological data collected from 1986 to 1990. Our model revealed a strong correlation between the NAO (North Atlantic Oscillation) index and biological production. The microbial food web (e.g. small phytoplankton, microzooplankton and bacteria) is more sensitive to climate variability than is the mesoplankton food web (e.g. large phytoplankton and mesozooplankton). Buoyancy flux-driven convective mixing, temperature and solar radiation are the major factors through which climate variability affects the function of cold-ocean ecosystems. KEY WORDS: Climate forcing · Vertical mixing · Phytoplankton bloom · Simulation modelResale or republication not permitted without written consent of the publisher

Seasonal and developmental variation in the fatty acid composition of Mysis mixta (Mysidacea) and Acanthostepheia malmgreni (Amphipoda) from the hyperbenthos of a cold-ocean environment (Conception Bay, Newfoundland)

“…The dense diatomaceous material produced during the bloom is quickly transferred to the bottom, and high concentrations of essential PUFA have been found in benthic organisms from Conception Bay (Parrish et al, 1996). Input of organic matter to the hyperbenthos decreases following the bloom, primarily because the increased dominance of the microbial food web results in retention of organic carbon within the upper mixed layer (Tian et al, 2003). By August, calanoid copepods that have accumulated lipid stores within the euphotic zone descend to begin diapause (Davis, 1982;D.…”

“…As is typical for Newfoundland fjords, the upper 50 m of Conception Bay is characterized by a successional pattern of plankton each year. Large diatoms generally dominate the plankton biomass early in the spring, whereas flagellates, bacteria and meso-and microzooplankton flourish in late summer/early autumn Tian et al, 2003). Consequently, hyperbenthic and benthic organisms experience a seasonal shift in food availability and quality.…”

Climate warming in winter affects the coupling between phytoplankton and bacteria during the spring bloom: a mesocosm study

“…In winter, temperatures may increase by as much as 5 to 10°C (prediction for the years 2070 to 2100 compared to the reference period 1960to 1990, IPCC 2001). Warming will have consequences for the aquatic food web in terms of its composition and the activity of its components at the different trophic levels (Beisner et al 1997, Tian et al 2003, Muren et al 2005. Light-dependent phototrophic ABSTRACT: The response of the phytoplankton and bacterial spring succession to the predicted warming of sea surface temperature in temperate climate zones during winter was studied using an indoor-mesocosm approach.…”

Seasonal and developmental variation in the lipids of Acanthostepheia malmgreni (Amphipoda) from the hyperbenthos of a cold-ocean environment (Conception Bay, Newfoundland)

“…; Tian et al, 2003). Inter-annual variation in lipid accumulation and maximum lipid level was not as pronounced in the sympatric Mysis mixta (Richoux et al, in press), which suggests that the mysids are better able to compensate for £uctua-tions in food availability and/or quality, owing to a high degree of motility, opportunistic feeding and the potential for diet switching.…”