Alongshore transport of a toxic phytoplankton bloom in a buoyancy current: Alexandrium tamarense in the Gulf of Maine

1992 ◽  
Vol 112 (1) ◽  
pp. 153-164 ◽  
Author(s):  
P. J. S. Franks ◽  
D. M. Anderson
Keyword(s):  
Gulf Of Maine ◽  
Phytoplankton Bloom ◽  
Alexandrium Tamarense ◽  
Toxic Phytoplankton

scholarly journals On the Dynamical Behavior of Toxic-Phytoplankton-Zooplankton Model with Delay

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Mehbuba Rehim ◽  
Weixin Wu ◽  
Ahmadjan Muhammadhaji
Keyword(s):  
Time Delay ◽  
Phytoplankton Bloom ◽  
Dynamical Behavior ◽  
Time Lag ◽  
Toxic Substance ◽  
Predation Rate ◽  
Dynamical Behaviour ◽  
Toxic Substances ◽  
Toxic Phytoplankton ◽  
Discrete Time Delay

A toxin producing phytoplankton-zooplankton model with inhibitory exponential substrate and time delay has been formulated and analyzed. Since the liberation of toxic substances by phytoplankton species is not an instantaneous process but is mediated by some time lag required for maturity of the species and the zooplankton mortality due to the toxic phytoplankton bloom occurs after some time laps of the bloom of toxic phytoplankton, we induced a discrete time delay to both of the consume response function and distribution of toxic substance term. Furthermore, based on the fact that the predation rate decreases at large toxic-phytoplankton density, the system is modelled via a Tissiet type functional response. We study the dynamical behaviour and investigate the conditions to guarantee the coexistence of two species. Analytical methods and numerical simulations are used to obtain information about the qualitative behaviour of the models.

scholarly journals Model study of nutrient and phytoplankton dynamics in the Gulf of Maine: patterns and drivers for seasonal and interannual variability

2014 ◽  
Vol 72 (2) ◽  
pp. 388-402 ◽  
Author(s):  
Rucheng Tian ◽  
Changsheng Chen ◽  
Jianhua Qi ◽  
Rubao Ji ◽  
Robert C. Beardsley ◽  
...  
Keyword(s):  
Interannual Variability ◽  
Gulf Of Maine ◽  
Phytoplankton Bloom ◽  
Function Analysis ◽  
Nutrient Supply ◽  
Open Boundary ◽  
Phytoplankton Production ◽  
Phytoplankton Dynamics ◽  
Salinity Regime ◽  
Dominant Feature

Abstract Coupled physical–biological modelling experiments were made for the period of 1995–2009 to analyse the spatial and interannual variability of nutrients and phytoplankton production in the Gulf of Maine (GOM). The physical model was the Finite-Volume Community Ocean Model (FVCOM) and the biological model was a Nitrogen, Phytoplankton, Zooplankton, and Detritus (NPZD) model. The simulation was carried out with realistic meteorological surface forcing, five major tidal constituents, river discharge, and observation-based open boundary conditions. The results were robust with comparison to SeaWiFS chlorophyll data and historical data of nitrogen. An Empirical Orthogonal Function analysis clearly identified two dominant modes in nutrient and phytoplankton dynamics: (1) sustained nutrient supply and phytoplankton production from spring through autumn, and (2) a dominating phytoplankton bloom in spring, relatively low production in summer, and a noticeable bloom in autumn. Mode 1 was a dominant feature in strong tidal energy dissipation regions such as the southwestern shelf of Nova Scotia, Georges Bank, Nantucket Shoals, the Bay of Fundy, and the coastal regions of GOM, where tidal pumping and mixing were the major drivers for the sustained nutrient supply, and primary production showed certain resilience with less interannual variability. Mode 2 was a characteristic in the deep Gulf, the offshore region of the Scotian Shelf, and in the open sea area, where the timing and amplitude of the spring phytoplankton bloom is essentially controlled by the salinity regime, and its interannual variability was significantly influenced by freshening events controlled by local and remote forcing.

Dinoflagellate Crop in the North Sea: Biological Observations associated with the Toxic Phytoplankton Bloom off the East Coast

Nature ◽  
1968 ◽  
Vol 220 (5162) ◽  
pp. 24-25 ◽  
Author(s):  
J. A. ADAMS ◽  
D. D. SEATON ◽  
J. B. BUCHANAN ◽  
M. R. LONGBOTTOM
Keyword(s):  
North Sea ◽  
East Coast ◽  
Phytoplankton Bloom ◽  
Toxic Phytoplankton ◽  
The North ◽  
The North Sea

Experience With Moored Observations in the Western Gulf of Maine From 2006 to 2012

2013 ◽  
Vol 47 (1) ◽  
pp. 19-32 ◽  
Author(s):  
James D. Irish ◽  
Douglas Vandemark ◽  
Shawn Shellito ◽  
Joseph E. Salisbury
Keyword(s):  
Ocean Acidification ◽  
Gulf Of Maine ◽  
Phytoplankton Bloom ◽  
Sonic Anemometer ◽  
Biophysical Modeling ◽  
Net Community Production ◽  
Direct Covariance ◽  
Environmental Laboratory ◽  
Flux Measurements ◽  
Isles Of Shoals

AbstractThe University of New Hampshire is studying CO2 gas exchange, ocean acidification, air-sea dynamics, and associated biological processes in the western Gulf of Maine. Two buoys provide data supporting these studies. The UNH CO2 buoy has been deployed jointly with the National Oceanic and Atmospheric Administration (NOAA)’s Pacific Marine Environmental Laboratory northeast of the Isles of Shoals since 2006. The Jeffreys Ledge Moored Observatory is a development mooring testing new techniques and is deployed east of Gloucester, MA. This mooring is testing the direct covariance measurement of wind stress using a 3-D sonic anemometer with a motion package to remove buoy motion effects. A fast-rate atmospheric CO2 sensor is mounted by the anemometer to evaluate its potential for direct covariance gas flux measurements. Both buoys have additional meteorological and oceanographic sensors to provide supporting measurements. Six years of CO2 buoy data have helped quantify the seasonal air-sea flux cycle of CO2 in the Western Gulf of Maine. The buoy is now a node in near-term ocean carbon cycle process control experiments and longer-term ocean acidification monitoring. The Jeffreys Ledge buoy momentum flux measurements using wind and motion measurements indicate reasonable first-order buoy motion corrections can be made. Also, buoy-induced flow disturbance requires postmeasurement corrections. Rapid buoy azimuthal rotations were corrected with the addition of a steering vane. A vertical array of oxygen sensors captures phytoplankton bloom signatures and provides net community production estimates that augment in-water SAMI-CO2 measurements and add to a robust system to support process studies and improved biophysical modeling within this region.

Predicting bycatch hotspots based on suitable habitat derived from fishery-independent data

2020 ◽  
Vol 641 ◽  
pp. 159-175
Author(s):  
J Runnebaum ◽  
KR Tanaka ◽  
L Guan ◽  
J Cao ◽  
L O’Brien ◽  
...  
Keyword(s):  
Habitat Suitability ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Gulf Of Maine ◽  
Homarus Americanus ◽  
Management Tool ◽  
American Lobster ◽  
Suitable Habitat ◽  
Climate Conditions ◽  
Suitability Index

Bycatch remains a global problem in managing sustainable fisheries. A critical aspect of management is understanding the timing and spatial extent of bycatch. Fisheries management often relies on observed bycatch data, which are not always available due to a lack of reporting or observer coverage. Alternatively, analyzing the overlap in suitable habitat for the target and non-target species can provide a spatial management tool to understand where bycatch interactions are likely to occur. Potential bycatch hotspots based on suitable habitat were predicted for cusk Brosme brosme incidentally caught in the Gulf of Maine American lobster Homarus americanus fishery. Data from multiple fisheries-independent surveys were combined in a delta-generalized linear mixed model to generate spatially explicit density estimates for use in an independent habitat suitability index. The habitat suitability indices for American lobster and cusk were then compared to predict potential bycatch hotspot locations. Suitable habitat for American lobster has increased between 1980 and 2013 while suitable habitat for cusk decreased throughout most of the Gulf of Maine, except for Georges Basin and the Great South Channel. The proportion of overlap in suitable habitat varied interannually but decreased slightly in the spring and remained relatively stable in the fall over the time series. As Gulf of Maine temperatures continue to increase, the interactions between American lobster and cusk are predicted to decline as cusk habitat continues to constrict. This framework can contribute to fisheries managers’ understanding of changes in habitat overlap as climate conditions continue to change and alter where bycatch interactions could occur.

Movements and foraging habitats of great shearwaters Puffinus gravis in the Gulf of Maine

2017 ◽  
Vol 574 ◽  
pp. 211-226 ◽  
Author(s):  
KD Powers ◽  
DN Wiley ◽  
AJ Allyn ◽  
LJ Welch ◽  
RA Ronconi
Keyword(s):  
Gulf Of Maine

Summer phytoplankton of the northern Barents Sea (75–80º N)

2019 ◽  
pp. 8-19
Author(s):  
Larisa A. Pautova ◽  
Vladimir A. Silkin ◽  
Marina D. Kravchishina ◽  
Valeriy G. Yakubenko ◽  
Anna L. Chultsova
Keyword(s):  
Barents Sea ◽  
Weighted Average ◽  
Arctic Basin ◽  
High Arctic ◽  
Alexandrium Tamarense ◽  
Warm Water ◽  
The Arctic ◽  
Absolute Maximum ◽  
Deep Trench ◽  
Maximum Biomass

The structure of the summer planktonic communities of the Northern part of the Barents sea in the first half of August 2017 were studied. In the sea-ice melting area, the average phytoplankton biomass producing upper 50-meter layer of water reached values levels of eutrophic waters (up to 2.1 g/m3). Phytoplankton was presented by diatoms of the genera Thalassiosira and Eucampia. Maximum biomass recorded at depths of 22–52 m, the absolute maximum biomass community (5,0 g/m3) marked on the horizon of 45 m (station 5558), located at the outlet of the deep trench Franz Victoria near the West coast of the archipelago Franz Josef Land. In ice-free waters, phytoplankton abundance was low, and the weighted average biomass (8.0 mg/m3 – 123.1 mg/m3) corresponded to oligotrophic waters and lower mesotrophic waters. In the upper layers of the water population abundance was dominated by small flagellates and picoplankton from, biomass – Arctic dinoflagellates (Gymnodinium spp.) and cold Atlantic complexes (Gyrodinium lachryma, Alexandrium tamarense, Dinophysis norvegica). The proportion of Atlantic species in phytoplankton reached 75%. The representatives of warm-water Atlantic complex (Emiliania huxleyi, Rhizosolenia hebetata f. semispina, Ceratium horridum) were recorded up to 80º N, as indicators of the penetration of warm Atlantic waters into the Arctic basin. The presence of oceanic Atlantic species as warm-water and cold systems in the high Arctic indicates the strengthening of processes of “atlantificacion” in the region.

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