Environmental factors influencing the biodeposition of the suspension feeding bivalve Dreissena polymorpha (Pallas): Comparison of brackish and freshwater populations     

Velda Lauringson  Evely Mlton  Jonne Kotta  Külli Kangur  Helen Orav-Kotta  Ilmar Kotta 《Estuarine, Coastal and Shelf Science》2007,75(4):459-467

Invasive suspension feeders have been particularly successful in shallow eutrophic estuarine and freshwater ecosystems. The impact of an invasive species is strong under favourable conditions. However, suboptimal feeding conditions may significantly reduce the impact to ambient environment. The invasive bivalve Dreissena polymorpha (Pallas) is able to colonize both fresh and brackish waterbodies. In an in situ experiment the seasonal variability in the biodeposition of D. polymorpha from fresh and brackish water populations was quantified at different temperature, salinity and chlorophyll a (Chl a) regimes. Salinity fluctuations in brackish water areas, temperature and water Chl a content were all important factors in the model of mussels' feeding. The results indicated that D. polymorpha fed significantly more in fresh than in brackish water. Mussels acclimated more easily to acute transfer from brackish to freshwater than vice versa. The biodeposition of zebra mussels increased with temperature and water Chl a content but these effects were less straightforward than that of salinity. The results suggest that the impact of D. polymorpha on recipient ecosystem is more pronounced in fresh than in brackish water environments.  相似文献   

Effects of the suspension feeding mussel Mytilus trossulus on a brackish water macroalgal and associated invertebrate community     

Jonne Kotta  Kristjan Herkül  Ilmar Kotta  Helen Orav-Kotta  & Velda Lauringson 《Marine Ecology》2009,30(S1):56-64

The importance of suspension-feeding mussels is particularly apparent in benthic communities; however, the role of this feeding strategy on the development of macroalgal and associated invertebrate communities is in general poorly known. The effect of suspension-feeding mussels Mytilus trossulus on benthic communities was studied in an in situ factorial field experiment in the Northern Baltic Sea over one ice-free season. The experiment was performed under different regimes of wave exposure (low and moderate) and on different sedimentary habitats (soft bottom with high organic content, soft bottom with low organic content, and hard bottom). In general the presence of mussels was associated with increased biomass of filamentous algae, herbivores and deposit feeders and decreased biomass of charophytes. The effect of M. trossulus interacted with the effect of exposure and substrate. Stronger responses were observed in moderately exposed than in sheltered areas. The presence of M. trossulus affected charophytes and deposit feeders on sand with low content of organic matter and filamentous algae on pebbles but not on other substrate types. The magnitude of the effects varied between months. The results suggest that (i) even in dynamic coastal systems the biodeposits and excretions of mussels are at least partly assimilated locally and are not flushed away to the open sea, (ii) the accumulation of faecal material induced elevated growth of deposit feeders, (iii) mussels enhanced the growth of ephemeral macroalgae and reduced the growth of perennial macroalgae, and (iv) together with increasing benthic primary production, mussels indirectly increase the production of herbivores.  相似文献   

Comparison of benthic and pelagic suspension feeding in shallow water habitats of the Northeastern Baltic Sea   总被引：1，自引：0，他引：1  

Velda Lauringson  Jonne Kotta  Helen Orav-Kotta  Ilmar Kotta  Kristjan Herkül  & Arno Põllumäe 《Marine Ecology》2009,30(S1):43-55

Combining field experiments with the biomass distribution data of dominant suspension feeders we compared the benthic and pelagic suspension feeding rates in shallow non-tidal brackish water coastal habitats. We found that pelagic grazing exceeded benthic grazing in almost all cases, on average from 14 to 4819 times depending on the site. Benthic grazing rates were related to site-specific environmental parameters and showed no relationship with water chlorophyl a (Chl a ) content, whereas pelagic grazing rates varied both spatially and temporally and were related to water Chl a content. Our results indicate that in several shallow coastal habitats, pelagic suspension feeding substantially exceeds benthic suspension feeding. This suggests that pelagic recycling is higher than the amounts of energy redirected from pelagic to benthic food webs by benthic suspension feeders. These results increase our knowledge of the energy flows in coastal ecosystems.  相似文献