The distribution gap is closed — First record of naturally settled pacific oystersCrassostrea gigas in the East Frisian Wadden Sea, North Sea

Wehrmann, Achim; Herlyn, Marc; Bungenstock, Friederike; Hertweck, Günther; Millat, Gerald

doi:10.1007/bf03042964

Cited by 63 publications

(54 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, the northwestern European shores are presently invaded by the introduced Pacific oyster Crassostrea gigas for which, at the time of its introduction in the 1960s, ambient water temperatures were considered too low for natural reproduction and settlement (e.g., Wehrmann et al 2000). Lowered adult stocks of edible coldwater species such as Macoma may reduce the carrying capacity of the system for bivalve-eating predators such as birds (for which these oysters are hardly edible; Cadée 2001), making it more vulnerable to depletion and disturbance as the result of shellfish fisheries (e.g., Camphuysen et al 2002;Stillman et al 2001).…”

Section: Predation Thresholdsmentioning

confidence: 99%

Climate‐related changes in recruitment of the bivalve Macoma balthica

Philippart¹,

Aken²,

Beukema³

et al. 2003

Limnology & Oceanography

236

194

View full text Add to dashboard Cite

Population dynamics of common intertidal bivalves (Cerastoderma edule, Macoma balthica, Mya arenaria, Mytilus edulis) are strongly related to seawater temperatures. In northwestern European estuaries, series of mild winters followed by low bivalve recruit densities lead to small adult stocks. In this study, we examine temperature-induced effects on reproductive output (eggs m Ϫ2 ), onset of spawning (day of the year), and the juvenile instantaneous mortality rate (per day) of M. balthica. Data analysis was based on an extensive long-term data set originating from the western Wadden Sea. Our results strongly suggest that rising seawater temperatures affect recruitment by a decrease in reproductive output and by spring advancement of bivalve spawning. Apparently, global warming upsets the evolved reproductive strategy of this marine bivalve to tune its reproduction to the most optimal environmental conditions for the first vulnerable life stages, most importantly the match/mismatch of time of spawning with that of the phytoplankton bloom and the settlement of juvenile shrimps on the tidal flats. It is hypothesized that the observed density-dependent mortality of juvenile bivalves may act via competition for food, a behavioral response of shrimp to low spat densities, or be the result of the response of age and size at metamorphosis of marine bivalves to resource variability. It is to be expected that prolonged periods of lowered bivalve recruitment and stocks will lead to a reformulation of estuarine food webs and possibly a reduction of the resilience of the system to additional disturbances, such as the depletion and disturbance by shellfish fisheries.

show abstract

Section: Predation Thresholdsmentioning

confidence: 99%

Climate‐related changes in recruitment of the bivalve Macoma balthica

Philippart¹,

Aken²,

Beukema³

et al. 2003

Limnology & Oceanography

236

194

View full text Add to dashboard Cite

show abstract

“…Contrary to all expectations, the foreign oyster species successfully reproduced and recruited outside the culture plots on intertidal mussel beds (Mytilus edulis) and artificial hard substrata. Probably favoured by warm summers, Crassostrea spread over the west, north and, most recently, east Frisian Wadden Sea and appears to have established itself as a permanent member of the Wadden Sea biotic community (Reise 1998;Wehrmann et al 2000). Compared to the native O. edulis, the life strategy of C. gigas is more opportunistic (more eggs per female and year, extended pelagic phase).…”

Section: Introductionmentioning

confidence: 99%

Long-term changes in the macrozoobenthos around the rocky island of Helgoland (German Bight, North Sea)

Franke

Gutow

2004

Helgol Mar Res

View full text Add to dashboard Cite

The paper briefly summarizes what is known about long-term changes (facts, causes, consequences) in the macrozoobenthos of intertidal and subtidal hardbottom communities around the island of Helgoland (German Bight, North Sea). There is increasing observational evidence that these communities (spectrum and abundances of species) are changing on a long-term temporal scale. The reasons are diverse and mainly anthropogenic. A shift in North Sea climate towards more oceanic conditions may be among the most important factors driving the recent changes in species spectrum. Many of the species which have been recorded as new to the Helgoland area during the past decade are southern (oceanic) species which may be considered as indicators of a warming trend.

show abstract

“…Oysters seem to grow up to 4 cm in the first year (this study ;Cadée 2000;Reise 1998;Wehrmann et al 2000;Schmidt et al 2008). Cadée (2000) also measured growth of second year oysters in the Mokbaai (Texel).…”

Section: Reproduction and Individual Growth Of Pacific Oystersmentioning

confidence: 57%

“…They can occur as clusters, patches or reefs. Although recruitment was irregular at first (Dankers et al 2004;Reise 1998;Wehrmann et al 2000), wild populations have increased at a dramatic pace since around the year 2000. Several factors might be of importance for this pattern of slow settlement followed by explosive growth.…”

Section: Discussionmentioning

confidence: 99%

“…In 1996 a first settlement occurred in the Niedersachsen part of the German Wadden Sea area, which may have dispersed from The Netherlands by natural means (Wehrmann et al 2000;Nehring 2003). In 1986 Pacific oysters were introduced in the Northern Wadden Sea at Sylt for cultivation (Reise 1998), and in 1991 the first oysters were found outside culture plots in the Northern Wadden Sea.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Development and distribution of the non-indigenous Pacific oyster (Crassostrea gigas) in the Dutch Wadden Sea

et al. 2009

View full text Add to dashboard Cite

Pacific oysters (Crassostrea gigas) were first observed in the Dutch Wadden Sea near Texel in 1983. The population increased slowly in the beginning but grew exponentially from the mid-1990s onwards, although now some stabilisation seems to be occurring. They occur on a variety of substrates such as mussel beds (Mytilus edulis), shell banks, dikes and poles. After initial settlement spat may fall on older individuals and congregate to dense clumps and subsequently form reefs. Individual Pacific oysters grow 3-4 cm long in their first year and 2-3 cm in their second year. Many mussel beds (Mytilus edulis) are slowly taken over by Pacific oysters, but there are also several reports of mussel spat settling on Pacific oyster reefs. This might in the end result in combined reefs. Successful Pacific oyster spat fall seems to be related to high summer temperatures, but also after mild summers much spat can be found on old (Pacific oyster) shells. Predation is of limited importance. Mortality factors are unknown, but every now and then unexplained mass mortality occurs. The gradual spread of the Pacific oyster in the Dutch Wadden Sea is documented in the first instance based on historical and anecdotal information. At the start of the more in-depth investigation in 2002, Pacific oysters of all size classes were already present near Texel. Near Ameland the development could be followed from the first observed settlement. On dense reefs each square metre may contain more than 500 adult Pacific oysters, weighing more than 100 kg per m 2 fresh weight.

show abstract

The distribution gap is closed — First record of naturally settled pacific oystersCrassostrea gigas in the East Frisian Wadden Sea, North Sea

Cited by 63 publications

References 6 publications

Climate‐related changes in recruitment of the bivalve Macoma balthica

Climate‐related changes in recruitment of the bivalve Macoma balthica

Long-term changes in the macrozoobenthos around the rocky island of Helgoland (German Bight, North Sea)

Development and distribution of the non-indigenous Pacific oyster (Crassostrea gigas) in the Dutch Wadden Sea

Contact Info

Product

Resources

About