Improving the Retrieval of Carbon-Based Phytoplankton Biomass from Satellite Ocean Colour Observations

Phytoplankton is at the base of the marine food web and plays a fundamental role in the global carbon cycle. Ongoing climate change significantly impacts phytoplankton distribution in the ocean. Monitoring phytoplankton is crucial for a full understanding of changes in the marine ecosystem. To observe phytoplankton from space, chlorophyll-a concentration (Chl) has been widely used as a proxy of algal biomass, although it can be impacted by physiology. Therefore, there has been an increasing focus towards estimating phytoplankton biomass in units of carbon (Cphyto). Here, we developed an algorithm to quantify Cphyto from space-based observations that accounts for the spatio-temporal variations of the backscattering coefficient associated with the fraction of detrital particles that do not covary with Chl. The main findings are: (i) a spatial and temporal variation of the detritus component must be accounted for in the Cphyto algorithm; (ii) the refined Cphyto algorithm performs better (relative bias of 23.7%) than any previously existing model; and (iii) our algorithm shows the lowest error in Cphyto across areas where picophytoplankton dominates (relative bias of 14%). In other areas, it is currently not possible to accurately assess the performance of the refined algorithm due to the paucity of in situ carbon data associated with nano- and micro-phytoplankton size classes.

Download Full-text

An ecosystem modeling study of spatio-temporal variations of phytoplankton distribution in the Okhotsk Sea

Continental Shelf Research ◽

10.1016/j.csr.2005.04.006 ◽

2005 ◽

Vol 25 (12-13) ◽

pp. 1605-1628 ◽

Cited By ~ 11

Author(s):

Takeshi Okunishi ◽

Michio J. Kishi ◽

Akihiro Shiomoto ◽

Hitoshi Tanaka ◽

Toshihiko Yamashita

Keyword(s):

Temporal Variations ◽

Ecosystem Modeling ◽

Okhotsk Sea ◽

Phytoplankton Distribution ◽

Spatio Temporal ◽

Modeling Study

Download Full-text

Environmental factors driving phytoplankton biomass and diversity in a tropical reservoir

Revista de la Academia Colombiana de Ciencias Exactas Físicas y Naturales ◽

10.18257/raccefyn.1052 ◽

2020 ◽

Vol 44 (171) ◽

pp. 423-436

Author(s):

Isabel Cristina Gil Guarín ◽

Silvia Lucía Villabona-González ◽

Edison Parra-García ◽

Ricardo O. Echenique

Keyword(s):

Transition Zone ◽

Phytoplankton Biomass ◽

Vertical Gradient ◽

Temporal Variations ◽

Water Levels ◽

Ex Situ ◽

Spatial And Temporal Variation ◽

Tropical Reservoir ◽

Vertical Scale ◽

Physical And Chemical Variables

We determined the spatial and temporal variation of phytoplankton biomass and diversity in 10 fortnightly sampling journeys verifying five sampling sites in El Peñol-Guatapé reservoir located in Antioquia, Colombia. In situ and ex situ physical and chemical variables were measured and phytoplankton samples were taken. Richness was dominated by Chlorophyta and biomass by Dinophyta. This variable was higher in the transition zone while in the riverine zone it showed average values, the lowest were registered in the lacustrine zone. Diversity was lower in the riverine zone, but it increased considerably in the transition zone and in the lacustrine zone where it showed similar values. At the vertical scale, biomass and diversity did not vary widely. Biomass showed a differential response to the effect of precipitation changes and water levels in the reservoir zones. Due to the low variability in environmental conditions, diversity was homogeneous time-wise. These results suggest that factors related to the hydrodynamic such as precipitation and water level resulting from the dam operation and inflow have a slight influence on the temporal variations of phytoplankton biomass and structure. There was a direct relationship between these attributes and physical variables such as turbidity and nutrients concentration at spatial scale while at the vertical scale, mixing patterns and the influence of the wind explained the absence of the vertical gradient of biomass and phytoplankton structure.

Download Full-text

Spatio-temporal variations of fish assemblages in seagrass ecosystem of Karang Congkak Island, Kepulauan Seribu

Jurnal Iktiologi Indonesia ◽

10.32491/jii.v19i3.486 ◽

2019 ◽

Vol 19 (3) ◽

pp. 491

Author(s):

Adinda Kurnia Putri ◽

Ridwan Affandi ◽

Charles P.H. Simanjuntak ◽

M. Fadjar Rahardjo

Keyword(s):

Fish Assemblages ◽

Juvenile Fish ◽

Common Species ◽

Temporal Variations ◽

Spatial And Temporal Variation ◽

Beach Seine ◽

Coastal Fisheries ◽

Siganus Canaliculatus ◽

Seagrass Ecosystem ◽

Spatio Temporal

Seagrass are globally known as an essential habitat for marine fishes. The study of fish assemblages in seagrass ecosystem is needed as the first base to select the most suitable coastal fisheries management. The study aims to reveal the composition of fish assemblages both seasonally and spatially in Karang Congkak Island, Kepulauan Seribu. Sampling was performed six times in NW monsoon (March), first transitional monsoon (April-May) and SE monsoon (Juni, August, September) 2018. Fish were sampled at four sites at seagrass ecosystem of Karang Congkak Island, namely eastern, southern, western, and northern by using beach seine net. The differences of juvenile fish assemblages were analyzed using One-Way ANOSIM. A total of 6,326 fish were collected belonging to 78 species, 31 families and 10 orders in which Labridae was the most diverse family. The result indicates strong spatial and temporal variation in fish composition. Fish compositions were dominated by juvenile both spatially and temporally. The most common species that inhabits seagrass beds of the Karang Congkak Island as temporary resident such as Gerres oyena and Siganus canaliculatus, and regular visitor namely Halichoeres argus. Cannonical correspondence analysis indicated strong correlation between several fish species and environmental variables.

Download Full-text

Spatial and temporal dynamics of Pacific capelin Mallotus catervarius in the Gulf of Alaska: implications for ecosystem-based fisheries management

Marine Ecology Progress Series ◽

10.3354/meps13211 ◽

2020 ◽

Vol 637 ◽

pp. 117-140 ◽

Cited By ~ 1

Author(s):

DW McGowan ◽

ED Goldstein ◽

ML Arimitsu ◽

AL Deary ◽

O Ormseth ◽

...

Keyword(s):

Temporal Dynamics ◽

Marine Ecosystem ◽

Gulf Of Alaska ◽

Data Series ◽

Limited Information ◽

Important Species ◽

Multiple Data ◽

Spatial And Temporal Dynamics ◽

Spawning Areas ◽

Spatio Temporal

Pacific capelin Mallotus catervarius are planktivorous small pelagic fish that serve an intermediate trophic role in marine food webs. Due to the lack of a directed fishery or monitoring of capelin in the Northeast Pacific, limited information is available on their distribution and abundance, and how spatio-temporal fluctuations in capelin density affect their availability as prey. To provide information on life history, spatial patterns, and population dynamics of capelin in the Gulf of Alaska (GOA), we modeled distributions of spawning habitat and larval dispersal, and synthesized spatially indexed data from multiple independent sources from 1996 to 2016. Potential capelin spawning areas were broadly distributed across the GOA. Models of larval drift show the GOA’s advective circulation patterns disperse capelin larvae over the continental shelf and upper slope, indicating potential connections between spawning areas and observed offshore distributions that are influenced by the location and timing of spawning. Spatial overlap in composite distributions of larval and age-1+ fish was used to identify core areas where capelin consistently occur and concentrate. Capelin primarily occupy shelf waters near the Kodiak Archipelago, and are patchily distributed across the GOA shelf and inshore waters. Interannual variations in abundance along with spatio-temporal differences in density indicate that the availability of capelin to predators and monitoring surveys is highly variable in the GOA. We demonstrate that the limitations of individual data series can be compensated for by integrating multiple data sources to monitor fluctuations in distributions and abundance trends of an ecologically important species across a large marine ecosystem.

Download Full-text