Environmental influences on the trawl catches in a bay-estuarine system of Goa, west coast of India

Ansari, Z.A.; Sreepada, R.A.; Dalal, S.G.; Ingole, Baban; Chatterji, Anil

doi:10.1016/s0272-7714(02)00201-9

Cited by 21 publications

(21 citation statements)

References 34 publications

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“…Coastal lagoons represent a distinct environment from estuarine channels, and in NSW represent only around 1.5% of the total wetland area (Kingsford et al 2004). The ecosystem services provided by such environments have been widely recognised (Woodward & Wui 2001) and are known to include moderating water quality (Faulkner 2004), providing key feeding and nursery habitats (Paerl 2010), and supporting coastal and offshore fisheries (Ansari et al 2003). While a critical balance between nutrient loads and flushing rates in coastal lagoons has been demonstrated (Webster & Harris 2004), much remains to be understood in terms of their links to other parts of the estuarine system and their responses to environmental and anthropogenic changes.…”

Section: Introductionmentioning

confidence: 99%

Modelling ecological change over half a century in a subtropical estuary: impacts of climate change, land-use, urbanization and freshwater extraction

Condie¹,

Hayes²,

Fulton³

et al. 2012

Mar. Ecol. Prog. Ser.

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The Clarence River Estuary is the largest estuary in southeast Australia, with an extensive floodplain encompassing multiple river channels and a large coastal lagoon. It is the focus of major commercial and recreational fisheries and there is pressure to divert its freshwater inputs for agricultural and domestic uses. We used a spatial biogeochemical model to simulate the variability and evolution of this system on timescales from days to decades over the past half century. Like most tropical and subtropical estuaries, the Clarence River Estuary is strongly influenced by river discharge, sediment and nutrient loads. Given the high nutrient loads arriving from the upper catchment, plankton biomasses in the model were typically limited by flushing through the estuary channels. However, the longer residence times of the lagoons produced a profoundly different regime where higher zooplankton concentrations were supported by recycling of nutrients and detritus. Using alternative model scenarios, it was found that the ecology of the lagoon was sensitive to changes in land-use and urbanization within the local sub-catchment, but was largely insensitive to changes in upstream river discharge (i.e. rainfall or freshwater extraction). The opposite was true in the estuary channels, where changes in land-use or urbanisation in the populated lower catchment had little effect on the estuarine ecology, while even modest reductions in river discharges dramatically increased the biomass of the smaller phytoplankton and zooplankton groups, and favoured benthic algae over seagrass and macroalgae. The contrasting responses of these 2 estuarine environments suggests the need for distinct management approaches, with stringent controls on nutrient loads into coastal lagoons and protection of environmental flows into estuary channels.

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Section: Introductionmentioning

confidence: 99%

Modelling ecological change over half a century in a subtropical estuary: impacts of climate change, land-use, urbanization and freshwater extraction

Condie¹,

Hayes²,

Fulton³

et al. 2012

Mar. Ecol. Prog. Ser.

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“…The sampling stations did not show much variation in temperature (air, water and sediment; (Ansari et al 2003) suggesting reduced oxygen conditions in surf-waters. Reduced oxygen levels could be due to the increased benthic biomass and respiratory activities of some aerobic bacteria, especially those that can mineralize hydrocarbon (which may have leaked from the grounded vessel) after an input of oil products (Bakke et al 1982).…”

Section: Environmental Parametersmentioning

confidence: 89%

Ecotoxicological effect of grounded MV River Princess on the intertidal benthic organisms off Goa

Ingole

Sivadas

Goltekar

et al. 2006

Environment International

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Abstract:The ecotoxicological effects of oil spill from the grounded vessel MV River Princess on the intertidal benthic organisms of Sinquerim -Candolim beach at Goa were investigated. An intertidal expanse of 1km on either side of the grounded vessel was selected to evaluate the concentration of Total Petroleum Hydrocarbon (TPH) in the sediment and its effects on the composition, abundance and diversity of micro-, meio-and macrobenthos. TPH in the intertidal sediment ranged from 7.8 to 89 µg g -1 (mean35.44 ± 26.35 SD). Microbenthos comprised of microalgae, protozoans and juvenile forms of meiobenthos. Apart from juvenile nematodes, which were abundant, Coscinodiscus spp, Navicula spp, and Nitzschia spp. representing microalgae were also observed in microbenthic samples. Meiobenthos was represented by 13 taxa and their total density ranged between 92-1057 no. 10cm -2 . Maximum meiobenthic abundance of 1057 no.10cm -2 was observed at Sinquerim. Nematodes were the dominant meiobenthic taxa followed by turbellarians and harpacticoid copepods. The macrobenthoc was numerically dominated by polychaetes, followed by crustaceans whereas bivalve molluscs were less represented. There was substantial increase in the petroleum concentration in the beach sediment compared to the previously reported values and highest TPH (89µg.g -1 sediment) values were in the vicinity of the grounded vessel. The polychaete/amphipod ratio and cumulative and partial dominance abundance-biomass curves showed significant negative impact of TPH on macrofauna. The benthic community structure also showed measurable changes, as there was significant decrease (60%) in the number of species. Given that the microalgal counts were low in sediment, it is assumed that the intertidal meiofauna was possibly using oildegrading bacteria as alternate food source. In conclusion, the results reported here suggest that the grounded ore carrier is not only detrimental to the beach community, that may take longer time for recovery, but also affect the beach morphology which may have long-term impact on local fishery.

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“…During the validation of the PFZ forecast we also collected the environmental variables along with the catch details. The structure and abundance of bayestuarine fish communities are greatly influenced by a wide variety of environmental variables (Ansari et al, 2003). Table 1 reflects the data of physico-chemical parameters analyzed during this study period.…”

Section: Pfz Validationmentioning

confidence: 99%

“…Conservative characteristics such as temperature and salinity are not influenced by the primary productivity of the system, but nonconservative characteristics such as dissolved oxygen, nutrient and chlorophyll-a concentrations are regulated directly or indirectly (Manasrah et al,, 2006). Although the abundance of fish can be correlated with environmental variables, the actions and interactions of these variables are often so complex that the causal relationships cannot be demonstrated unequivocally (Ansari et al, 2003). The Bay of Bengal (BOB) is unique because of its large seasonal freshwater input, which makes the waters layers of the northern part of this bay less saline and highly stratified.…”

Section: Introductionmentioning

confidence: 99%

“…Gordon et al (2002) and Prasanna et al (2007). Ansari et al (2003) studied the marine fish catch and physico-chemical parameters in the Goa coast of India. They performed principal component analysis (PCA) and found that dissolved oxygen (DO), chlorophyll-a, macrobenthic density, sediment-pH and particulate organic carbon (POC) are of primary importance, whereas salinity, temperature, zooplankton density, macrobenthic biomass and pH are of secondary importance among environmental factors controlling the temporal variations in trawl catches in the bay-estuarine system of Goa.…”

Section: Introductionmentioning

confidence: 99%

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Dutta¹,

Chanda²,

Akhand³

et al. 2016

Turk. J. Fish. Aquat. Sci.

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The paper discusses the correlation between the Catch per Unit Effort (CPUE) of fishes with the phytoplankton biomass (chlorophyll-a) and nutrients in the West Bengal marine fishing zone (northern Bay of Bengal) during the post-monsoon season of 2010-11 and 2011-12. A total of 12 Potential Fishing Zone forecasts were simultaneously validated on board, covering 70 random samplings points wherein the physico-chemical parameters were also measured. A strong positive correlation of the CPUE with phytoplankton biomass was observed. The CPUE also positively correlated with the essential nutrients like dissolved inorganic phosphate (DIP), dissolved inorganic nitrate (DIN) and silicate. Four components were figured out in the principal component analysis out of 11 environmental variables. The first component primarily consisted of salinity, Secchi depth (positive loadings), turbidity and dissolve oxygen (DO) (negative loadings). Increases in component 2 were associated with increases in nutrients (silicate, nitrate and phosphate). The CPUE was much higher (8.15±6.08 kg/hour) in the PFZ forecast zones compared to the areas outside the forecast area (3.51±1.61 kg/hour).

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Environmental influences on the trawl catches in a bay-estuarine system of Goa, west coast of India

Cited by 21 publications

References 34 publications

Modelling ecological change over half a century in a subtropical estuary: impacts of climate change, land-use, urbanization and freshwater extraction

Modelling ecological change over half a century in a subtropical estuary: impacts of climate change, land-use, urbanization and freshwater extraction

Ecotoxicological effect of grounded MV River Princess on the intertidal benthic organisms off Goa

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