Changes in the ecological balance of invertebrate communities in kelp holdfast habitats of some polluted North Sea waters

Abstract

KURZFASSUNG: Veriinderungen des 6kologischen Gleichgewichts von Invertebraten-Lebensgemeinschaiten in Habitaten der HaPcorgane yon Tangen elniger verunreinigter Nordseegewiisser. Die durch Wasserverunreinigungen bedingten r~iurnlichen und zeitlichen Veriinderungen der Lebensgemeinschafien yon Invertebraten, die auf dem Hattorgan der Braunalge Larninaria hyperborea G~NN. FosL~ siedeln, wurden untersucht. Alle Beobachtungen beziehen sich auf die nord/Sstliche Kiiste Englands und die siidwestliche Kiiste Schottlands. Die Arbeit schlieflt sich an eine friihere Ver~Jffentlichung (JoNrs 1971) an, in der die chemischen, physikalischen und biologischen Faktoren behandelt wurden, welche die verschmutzten Kiistengebiete charakterisieren. Dabei wurde unterschieden zwischen der j~ihrlichen Zuwachsrate des Ha~organ-Habitats (gemessen in mm ~ ,,ecospace") und der Besiedlungsrate (,ecoperiod"). Die Ergebnisse zeigen, daft die Entwickiung der Epifauna auf Laminaria hyperborea in einern Radius yon ungeflihr 50 krn um den Firth of Forth und in einem Bereich yon 100 km in offenen, verschmutzten Kiistengewlissern verlangsamt ist. In verunrelnigten Kiisten-gew~issern entsteht eine wenig stabile Nahrungskette, die sich auf Detritus aufbaut. Der periodische Verlust einiger nur kurzfristig siedelnder Arten scheint zu bewirken, daft sich die BioziSnose nicht unabh~ingig yon benachbarten, in unverschmutzten Gebieten vorkommenden marinen Gemeinscha~en entwickeln kann. Die m6glichen Dauerfolgen der Verschmutzung auf derartige neotene Lebensgemeinschal°cen werden diskutiert.

Effects of pollution on holdfast macrofauna of the kelp Ecklonia radiata :discrimination at different taxonomic levels

“…A reduction in both crustaceans and ophiuroids has been noted for other macrofaunal communities under the influence of effluent discharge (Rosenberg 1973, Hoare & Hiscock 1974, Pearson & Rosenberg 1978, Cross & Ellis 1981 In addition, the increased abundance of suspension-feeding organisms including bivalves has already been documented for holdfast communities subjected to organic enrichment (Jones 1972, Smith & Simpson 1992. The observation that polychaetes (annelids at the phylum level of aggregation) were reduced in dominance adjacent to the outfall is however contrary to previous work (Hoare & Hiscock 1974, Pearson & Rosenberg 1978.…”

Potential novel habitat created by holdfasts from cultivated Laminaria digitata: assessing the macroinvertebrate assemblages

“…In this respect it is remarkable that suspended kelp were only in the sea for 11−13 mo, but had higher species richness than adjacent holdfasts from an established kelp bed. Even though holdfasts have been shown to be the tissues hosting the highest richness and abundance of fauna on kelp (Jones 1972, Moore 1972, Christie et al 2003, the stipe and frond faunal communities can host different assemblages in terms of composition and structure (Christie et al 2003) and, thus, also need to be analysed. If the communities associated with suspended kelps were found to be beneficial to the ecosystem, different harvesting techniques could be employed to maintain the holdfast, stipe and some frond material to allow the community to continue to grow.…”

“…Sloane et al 1957, Schultze et al 1990, Christie et al 2003. The holdfast is generally found to host more species than other parts of the kelp (Jones 1972, Moore 1972, Thiel & Vásquez 2000, Arroyo et al 2004. The relatively high biodiversity of the holdfast is thought to reflect the benefits of a more complex physical structure (the spaces within the holdfast as compared to relatively smooth stipes and fronds), a more sheltered and sediment-rich local environment and the longer time available for colonization when compared to annually renewing parts of the kelp, like fronds (Christie et al 2003(Christie et al , 2007.…”

Changes in invertebrate assemblages inhabiting Lessonia spicata (Phaeophyceae) holdfasts after the 2010 earthquake-mediated coastal uplift in Chile

“…Many studies have highlighted the use of kelp holdfasts faunal assamblages as bio-monitor following environmental perturbations (e.g., Jones 1972, Smith & Simpson 1993, Smith et al 1996, Smith 2000, Sáez et al RESEARCH NOTE 2012. In this study we took advantage of the coseismic uplift in Chile to study the effects of changes in the vertical positioning of the L. spicata belts on the structure of fauna inhabiting uplifted holdfasts (UH), to that occurring in new non-uplifted holdfasts (NH) (Fig.…”