Biological and physical aspects of migration in the estuarine amphipod Gammarus zaddachi

Hough, A. R.; Naylor, E.

doi:10.1007/bf00356289

Cited by 18 publications

(16 citation statements)

References 5 publications

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“…The peak in abundance recorded at West Thurrock is therefore likely to represent G. zaddachimoving into this part of the estuary to reproduce, returning upstream again in autumn. Hough & Naylor (1992) reported the seaward areas of the Conway Estuary (N. Wales) were depopulated in winter; this trend is also apparent in the Thames. Previous studies have linked the seasonal migrations of G. zaddachi to both salinity (e.g.…”

Section: Discussionmentioning

confidence: 90%

Modelling estuarine Crustacea population fluctuations in response to physico-chemical trends

Attrill¹,

Power²,

Thomas³

1999

Mar. Ecol. Prog. Ser.

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Regular samples (generally every 2 wk) of 6 estuarine crustacean species, Carcinus maenas, Liocarcinus holsatus, Crangon crangon, Palaemon longirostris, Palaemon serratus and Gamrnarus spp. (mainly G. zaddachi), were taken over a 12 yr period from the cooling water intake screens of West Thurrock power station on the Thames estuary, UK. Additionally, comparative data sets for abiotic variables (freshwater flow, salinity, temperature, dissolved oxygen, pH, suspended solids, total nitrogen) were collected for the same time period. The comprehensive nature of the time series, and accompanying suite of variables, allowed the construction of statistical models for the trends in populat.ion abundance of the 6 species uslng multlple linear regression techniques. Statistically significant models were constructed for C. maenas, C. crangon and Gammarus spp., accurately predicting annual, and longer term, fluctuations in abundance. All models had strong seasonal components, although for C. maenas temperature was the only physico-chemical vanable w~t h significant explanatory power The importance of temperature as a controlhng variable for the specles was reinforced by the inclusion of an instrumental variable to simulate a threshold temperature for foraging activity. The optimal value was found to be 8°C. C. crangon was found to be positively correlated with dissolved oxygen, but showed a slight decline in abundance over the time period. There was no significant relationship with either salinity or temperature, variables previously suggested as belng important. Gammarus spp. abundance had 2 significant explanatory variables (temperature and salinity) but also demonstrated a large decrease in population size with time. L. holsatus and P. serratus are summer-occurring species, so were recorded too infrequently to adequately capture seasonal dynamics. Despite the long time series, no significant model was possible for P. longirostris abundance (non-normal residuals), which has been suggested previously as having a strong relationship with salinity. The results of the study provide the first significant multiple linear regression models that accurately predict estuarine crustacean abundance. Whilst these models are useful for helping to understand variability in the Thames, it will be interesting to determine whether populations in other estuaries demonstrate relationships with similar suites of physico-chemical parameters.

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Section: Discussionmentioning

confidence: 90%

Modelling estuarine Crustacea population fluctuations in response to physico-chemical trends

Attrill¹,

Power²,

Thomas³

1999

Mar. Ecol. Prog. Ser.

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“…population. Whilst this change may be explained by an upstream movement of the population following the reduction in flows (Attrill 1998, Attrill et al 1999, the main Gammarus species comprising the samples from the Thames, G. zaddachi, is known to undertake summer reproductive migrations into more saline water (Hough & Naylor 1992), and thus large numbers of individuals would be expected to be sampled at West Thurrock during the summer months. This was not evident during the drought period, and the population size was decreasing prior to the onset of drought, so a real reduction in Gammarus spp.…”

Section: Discussionmentioning

confidence: 99%

Effects on invertebrate populations of drought-induced changes in estuarine water quality

Attrill¹,

Power²

2000

Mar. Ecol. Prog. Ser.

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Between the years 1989 and 1992, severe drought conditions occurred in the Thames estuary catchment, significantly reducing freshwater flows into the estuary and affecting estuarine water quality. Long-term data assembled for water quality between 1977 and 1992 were combined with invertebrate abundance data obtained from the intake screens of West Thurrock power station over the same period. This allowed an examination of the influence of drought-induced changes in water-quality parameters on the populations of the most abundant mobile estuarine invertebrates. For 8 invertebrate species, seasonal and monthly means for pre-drought (1977 to 1988) and drought (1989 to 1992) abundances were calculated and tested for significant differences. Time-series data were used to estimate regression models explaining observed variations in populations of Carcinus maenas, Crangon crangon and Gammarus spp. during both periods. Stability tests were used to establish significant differences in pre-drought and drought models. Significant mean seasonal and monthly differences were found for C. maenas and Gammarus spp. in both winter and summer, with significant summer differences being apparent for C. crangon and Palaemon longirostris. Regression analyses confirmed these results for the modelled species and highlighted the significance of drought-related changes in temperature for all 3 crustaceans, with dissolved oxygen being an additional significant variable for C. crangon. The reported significant changes in abundance of the studied species during drought conditions have important implications for the structure and dynamics of estuarine food webs, as C. maenas, Gammarus spp., and particularly C. crangon, are either important predators on invertebrates and juvenile fish or major food items for estuarine fish species.KEY WORDS: Thames · Drought · Models · Carcinus maenas · Crangon crangon · Gammarus · Crustacea · Cnidaria · Ctenophora · Temperature · OxygenResale or republication not permitted without written consent of the publisher

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“…[16] Furthermore, P. gualpensis showed a U-shaped distribution pattern typically found in estuarine animals. [28] It ensures the middle areas as proper sites for inter-estuarine comparisons according to the highest densities and the best scenario for the population development within an estuary.…”

Section: Discussionmentioning

confidence: 99%

Spatio-temporal population and reproductive responses inPerinereis gualpensis(Polychaeta: Nereididae) from estuaries under different anthropogenic influences

Díaz-Jaramillo

Sandoval

Barra

et al. 2015

Chemistry and Ecology

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Reproductive and population-level responses are ecologically relevant diagnostic tools for revealing the cost of long-term tolerance to contaminants. Spatial density distribution, seasonal density, biomass, size frequency histograms and oocytes stages in Perinereis gualpensis (Polychaeta: Nereididae) from a highly anthropogenically impacted estuary (Lenga, south-central Chile) were compared with low-polluted estuaries (Tubul and Raqui). Spatial distribution showed that the highest P. gualpensis abundances occur in the central (middle) estuarine area, establishing them as suitable zones for comparisons of estuaries. Middle areas also showed differences among estuaries in terms of population and reproductive responses. Mature stage oocytes and juvenile recruitment limited to certain seasons and low adult survival led to significant low densities and biomasses in Lenga individuals (p < .05). Conversely, high densities and biomass, continuous recruitment and mature oocyte occurrence were observed in Tubul-Raqui estuaries. These results reflected population and reproductive differences among high-and low-polluted estuaries, suggesting that chronic pollution status in Lenga estuary is a factor to be considered when evaluating these responses.

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Biological and physical aspects of migration in the estuarine amphipod Gammarus zaddachi

Cited by 18 publications

References 5 publications

Modelling estuarine Crustacea population fluctuations in response to physico-chemical trends

Modelling estuarine Crustacea population fluctuations in response to physico-chemical trends

Effects on invertebrate populations of drought-induced changes in estuarine water quality

Spatio-temporal population and reproductive responses inPerinereis gualpensis(Polychaeta: Nereididae) from estuaries under different anthropogenic influences

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