Germination and anchorage ofEnteromorpha spp. in sediments of the Wadden Sea

Schories, Dirk; Reise, Karsten

doi:10.1007/bf02367169

Cited by 49 publications

(38 citation statements)

References 25 publications

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“…and Ulva sp. biomass were very low this positive correlation can be explained by the fact that an organic enrichment may favour algal development [15,18,21,23,25,30,40,44]. In addition, grazing activity on periphyton and epiphyte may favour the macrophytes [22,42], and therefore food resources were always available for H. ulvae [16,20,24,36].…”

Section: Environmental Factorsmentioning

confidence: 99%

Population structure, dynamics and production of Hydrobia ulvae (Pennant) (Mollusca: Prosobranchia) along an eutrophication gradient in the Mondego estuary (Portugal)

1999

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-Eutrophication in the Mondego estuary gave rise to qualitative changes in the benthic community, involving the replacement of eelgrass, Zostera noltii, by green algae such as Enteromorpha spp. and Ulva sp. It seems reasonable to assume that, through time, such changes may determine a selected new trophic structure. Hydrobia ulvae, a dominant species in terms of abundance and biomass, was studied with regard to life history, population dynamics and productivity in relation to changing environmental conditions along the eutrophication gradient. The purpose was to examine to what extent this species may adapt to the new emergent conditions. During the study period, H. ulvae population exhibited both temporal and spatial density variations. The settlement pattern did not change along the eutrophication gradient, and took place in March, June, July and September. However, the population was denser in the less eutrophied areas, corresponding to Z. noltii meadows, when compared to the eutrophied ones, where Enteromorpha spp. blooms are usually observed. Growth was continuous through life but growth rates were higher during spring, decreased from early summer to mid fall and practically ceased during winter, and then gradually increased again up to spring. Life span was estimated as 21 ± 3 months. Growth productivity (P) was estimated as 93.7 g AFDW⋅m ⋅year -1 in the strongly eutrophied area. The average annual biomass (B √ ) (standing stock) of the population was estimated as 70.2 g AFDW⋅m -2 in the Z. noltii meadows, 5.5 g AFDW⋅m -2 in the eutrophied area, and 7.4 g AFDW⋅m -2 in the strongly eutrophied area. P/B √ and E/B √ ratios were estimated as 1.3 and 4.8 in the Z. noltii meadows, 2.8 and 9.5 in the eutrophied area, and 4.5 and 13.2 in the strongly eutrophied area, respectively. As a pattern, the standing stock decreased as a function of increasing eutrophication, while P/B √ and E/B √ ratios increased following the same gradient. There is evidence that H. ulvae population structure and annual production are seriously affected by eutrophication, namely by macroalgal bloom dynamics. Moreover, results suggest that H. ulvae might be suffering a change in its adaptive strategy along the eutrophication gradient, becoming closer to a typical 'r' strategist in the strongly eutrophied areas. © 1999 Éditions scientifiques et médicales Elsevier SAS Eutrophication / Hydrobia ulvae / life cycle / population dynamics / productivity

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Section: Environmental Factorsmentioning

confidence: 99%

Population structure, dynamics and production of Hydrobia ulvae (Pennant) (Mollusca: Prosobranchia) along an eutrophication gradient in the Mondego estuary (Portugal)

1999

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“…In the Wadden Sea, Hydrobia may play a positive role in the development of macro-algal mats by providing a suitable substrate for settlement and germination (Schories and Reise 1993). Live Hydrobia were collected from two areas on the Ythan during the summer from two sites: one with a long history of macro-algal blooms (Inches) and a second site (Macharmuir) where macroalgae are rare or absent (Shearer 1997).…”

Section: Effects Of Invertebrates On Macro-algaementioning

confidence: 99%

Interactions between macro-algal mats and invertebrates in the Ythan estuary, Aberdeenshire, Scotland

Raffaelli¹

2000

Helgoland Marine Research

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Blooms of opportunistic green macro-algae are a common feature of coastal areas and their effects on mudflat invertebrates can be dramatic. On the Ythan estuary, Aberdeenshire, Scotland, we have carried out a number of manipulative field experiments designed to evaluate the effects on invertebrates of different species of macro-algae with contrasting ecologies, and the effects of invertebrates on the development of the blooms. Macro-algal mats were found to have dramatic negative effects on the density of the amphipod Corophium volutator, with higher algal biomasses having greater impact. The mechanism for this interaction seems to be interference by the algal filaments with the feeding behaviour of the amphipod. In contrast, the polychaete Capitella spp. increases in abundance under macro-algal mats due to enrichment of the sediment with organic material. These two interactions are seen at all scales, in areas of less than 1 m 2 to the scale of the entire estuary, irrespective of the species composition of the macroalgal mats. Bioturbation by Corophium and grazing by the snail Hydrobia ulvae had little effect on macro-algal biomass, but there were less algae when the polychaete Nereis diversicolor was present. The most significant interaction in this system is the pronounced negative impact of algal mats on the abundance of Corophium, probably the most important invertebrate species in the diets of the estuary's shorebirds, fish and epibenthic crustaceans.

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“…9) Enteromorpha spp. After germination in early spring (Schories, 1991), algae attach to solid substrates such as worm tubes, mollusc shells and stones (Reise, 1983;Schories & Reise, 1993). In May a rapid growth starts due to higher temperatures and longer light periods.…”

Section: Recovery Of Meiofauna After Re-establishment Of Oxidized Sedmentioning

confidence: 99%

“…eutrophication (De Jonge & Essink, 1991;Beukema, 1992;Brockmann et aL, 1994;Asmus et aL, 1994;Michaelis & Reise, 1994;Kolbe et aL, 1995). Eutrophication in estuaries and coastal waters is well documented and may explain the increased growth of certain species of epibenthic macroalgae that take advantage of such conditions (Schories & Reise, 1993;. Increasing degradable organic matter may strongly affect the biogeochemical cycling and nutrient processes (Conley & Johnstone, 1995) and lead to oxygen depletion (Kelly & Nixon, 1984), as well as to accumulation of toxic sulphide (Holmer & Kristensen, 1994;Osinga et aL, 1995) even at the surface sediment layer.…”

Section: Introductionmentioning

confidence: 99%

Black spots produced by buried macroalgae in intertidal sandy sediments of the Wadden Sea: Effects on the meiobenthos

Neira¹

1996

Netherlands Journal of Sea Research

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The effects of buried decaying macroalgae on meiobenthos were examined in intertidal sandy sediments of the Wadden Sea of Lower Saxony. In situ experiments confirmed that one of the principal causes of the formation of reduced surface sediments or 'black spots' on the tidal flats is the increasing occurrence and subsequent decomposition of filamentous green algae (Enteromorpha spp.) buried in the sediment. Five to fifteen days after algal material had been buried, the sediment surface turned black. The impact of these black spots on meiobenthos was dramatic: the changed chemical conditions in the sediment resulted in long and drastic reductions in meiofaunal abundance and number of taxa. A multi-dimensional scaling (MDS) analysis of data on meiobenthic abundances revealed that samples from black-spot areas were clearly separated from those of control and reference areas. Re-oxidized black spots showed recolonization by meiofaunal animals, with numbers of individuals and taxa similar to those of oxidized surface sediments. The use of abundances of members of higher meiobenthic taxa to monitor changes in the sediment's chemistry, especially those caused by biomass overload, is discussed.

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Germination and anchorage ofEnteromorpha spp. in sediments of the Wadden Sea

Cited by 49 publications

References 25 publications

Population structure, dynamics and production of Hydrobia ulvae (Pennant) (Mollusca: Prosobranchia) along an eutrophication gradient in the Mondego estuary (Portugal)

Population structure, dynamics and production of Hydrobia ulvae (Pennant) (Mollusca: Prosobranchia) along an eutrophication gradient in the Mondego estuary (Portugal)

Interactions between macro-algal mats and invertebrates in the Ythan estuary, Aberdeenshire, Scotland

Black spots produced by buried macroalgae in intertidal sandy sediments of the Wadden Sea: Effects on the meiobenthos

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