Biodiversity as an index of regime shift in the eastern Bering Sea

Data collected from an annual groundf ish survey of the eastern Bering Sea shelf from 1975 to 2002 were used to estimate biomass and biodiversity indexes for two fish guilds: f latfish and roundfish. Biomass estimates indicated that several species of f latfish (particularly rock sole, arrowtooth flounder, and f lathead sole), several large sculpins (Myoxocephalus spp.), bigmouth (Hemitripterus bolini), and skates (Bathyraja spp.) had increased. Declining species included several f latfish species and many smaller roundfish species of sculpins, eelpouts (Lycodes spp.), and sablefish (Anoplopoma fimbria). Biodiversity indexes were calculated by using biomass estimates for both guilds from 1975 through 2002 within three physical domains on the eastern Bering Sea shelf. Biodiversity trends were found to be generally declining within the roundfish guild and generally increasing within the f latfish guild and varied between inner, middle, and outer shelf domains. The trends in biodiversity indexes from this study correlated strongly with the regime shift reported for the late 1970s and 1980s.

The biodiversity issue takes to the water

This material is based on an EarthAction Network which consists of more than 750 citizen groups in 101 countries. Some general and aquatic biological diversity problems and possible solutions to these problems are presented.

Biodiversity research and ICLARM

ICLARM's current and medium-term activities on biodiversity research in the fields of fisheries and aquaculture are summarized in this article.

Biodiversity of estuarine fish faunas in West Africa

In West Africa (between Ivory Coast and Sénégal), estuarine environments vary from lagoons to high discharge rivers to inverse hypersaline estuaries. This results in a high diversity of estuarine fish species, with an important turnover and a core of ubiquitous species. The species richness of a given estuary depends on the combination of hydrological factors (marine or freshwater dominance) and biogeography (continental biogeographic regions). The catch rate is higher in lagoons and inverse estuaries than in normal estuaries, which can be explained by the predominance of small juveniles in the latter. Clupeids are the most abundant fishes all over the region, but different systems have different dominant species. Assessing the functioning of West-African estuaries provides useful comparisons to Asian estuarine systems.

Bilboko Eraztun Berdeko ekosistemek eskaintzen dituzten zerbitzuen azterketa eta erabiltzaileen pertzepzioa

[EUS] Hiriko ekosistemak garrantzi handiko gune berdeak bilakatzen ari diren honetan, geroz eta gehiago dira eremu naturalen kudeaketarako estrategiak garatzeko biodibertsitatearen eta ekosistemen zerbitzuen balioa kontuan hartu behar dela uste dutenak. Ekosistemen zerbitzuen (gizakiak ekosistematik eskuratzen dituen onurak) kudeaketa jasangarria garatzeko, zerbitzuon eskaintza eta eskaria kontuan hartzen dituzten aspektu biofisiko, sozio-kultural eta ekonomikoak ezagutzea beharrezkoa da. Ikerketa honetan, hiritarrek Bilboko Eraztun Berdeko ekosistemek eskaintzen dituzten zerbitzuen inguruan duten pertzepzioa ezagutu nahi da, jendeak eskaintzen diren zerbitzu guztiak hautematen dituen jakiteko. Horretarako, ikertutako arean ekosistemen hiru zerbitzu kartografiatu dira (aspektu biofisikoa) eta 111 pertsona inkestatu dira euren iritzia ezagutzeko (aspektu sozio-kultural eta ekonomikoa). Hala, ikusi da hiritarrek naturak ongizaterako duen garrantzia ezagutzen dutela, nahiz eta ekosistemen zerbitzuen kontzeptua ez ezagutu. Dena dela, ekosistemak egoera onean mantentzeko prest daude, bereziki garrantzitsuak iruditzen baitzaizkie erregulaziozko zerbitzuak (airearen kalitatea) eta zerbitzu kulturalak (lasaitasuna, aisia, eta naturarekin kontaktua). Beraz, emaitza hauek kontuan hartu beharko lituzkete Bilboko Eraztun Berdeko ekosistemen kudeaketaz arduratzen diren agintariek, etorkizun hurbilean zerbitzuen eskaintza eta eskariaren arteko kudeaketa orekatua garatzeko.

Impacto de las aguas residuales urbanas sobre las comunidades de macroalgas intermareales: caso practico en la Reserva de la Biosfera de Urdaibai

[ES] Las aguas residuales domésticas asociadas a los núcleos urbanos se encuentran entre los principales impactos antrópicos que amenazan la biodiversidad de los ecosistemas costeros. El presente trabajo tiene como objetivo evaluar el impacto de aguas residuales provenientes de la población de Bermeo sobre las comunidades intermareales de la parte mas externa de la Reserva de la Biosfera de Urdaibai. Para ello se ha contrastado la estructura de la vegetación bajo la influencia del emisario con la existente en cuatro localidades control en los años 2013 y 2014. Los resultados reflejan diferencias en la composición de la flora intermareal entre la localidad impactada y las localidades no afectadas por la contaminación. La localidad impactada queda caracterizada por la proliferación de algas filamentosas (Bachelotia antillarum) y clorófitos (Ulva intestinalis), así como de rodofíceas cespitosas con corticación simple (Gellidium pusillum, Gellidium pulchellum y Caulacanthus ustulatus). Por el contrario, en las localidades control son abundantes las especies perennes de gran porte y morfología compleja (Bifurcaria bifurcata, Cystoseira tamariscifolia, Halopteris spp. y Gelidium corneum). La calcárea Coralina elongata, estaba presente tanto en las localidades control como en la localidad impactada. Por otra parte, los análisis de la varianza realizados detectaron una elevada variabilidad espacio-temporal en la composición multivariable de la vegetación intermareal de las estaciones control, lo cual restó poder estadístico para detectar las diferencias entre la localidad impactada y los controles. Este resultado pone de manifiesto la dificultad e importancia de elegir controles apropiados para detectar impactos ambientales. Este estudio ha proporcionado la información necesaria sobre el estado ecológico de las comunidades en la situación pre-operacional de la EDAR de Lamiaran (Bermeo), lo cual permitirá evaluar en un futuro la eficacia del tratamiento de las aguas en términos de recuperación biológica.

Genetic enhancement and conservation of aquatic biodiversity in Africa

There is a pressing need to enhance fish production in Africa through improved farm management and the use of improved fish breeds and/or alien species in aquaculture while at the same time conserve the aquatic genetic diversity. This paper presents the outcome of the Expert Consultation on Biosafety and Environmental Impact of Genetic Enhancement and Introduction of Improved Tilapia Strains/Alien Species in Africa held in Nairobi, Kenya on 20-23 February 2002. The main topics discussed were status of aquaculture in Africa and the role of genetic enhancement; potential benefits and risks involved in introduction of genetically improved strains and/or alien species with specific reference to tilapias; existing policies and legislation for the conservation of biodiversity, their strengths and weaknesses; capacity for undertaking genetic enhancement research and implementation of policies for the conservation of aquatic biodiversity.

Ecosystem function and biodiversity on coral reefs

The article highlights a workshop held in Key West, Florida in November 1993 attended by a group of 35 international scientists where topics of ecosystem function and biodiversity on coral reefs were discussed.

Marine fisheries, genetic effects and biodiversity

Preservation of marine biodiversity deserves serious consideration as almost 65% of the earth's organisms (excluding insects) are marine. There is little knowledge at present on the status of marine biodiversity. However, the seas are an important source of protein for human consumption and genetic diversity is a key factor in ecosystem functioning, stability and resilience. Overfishing and destructive practices may have unalterable impact on marine biodiversity. This paper discusses measures that can be adopted to protect the most productive areas of the marine ecosystem.

European Union supports project to strengthen fisheries and biodiversity management in African, Caribbean, and Pacific (ACP) countries

Proper resource management implies a better understanding of ecosystems and the conservation of biodiversity. Scientists from developing countries often have limited information on their aquatic resources because of many difficulties in accessing and exchanging information on a national and international level. The project described not only aims to strengthen the scientific capacity of fisheries scientists in ACP institutions but it is also expected to create an awareness among fisheries researchers and managers of the importance of conserving biodiversity for the sustainable use of living aquatic resources. This will be achieved through training, building a network of regional and transregional cooperation using modern communication facilities, the promotion of research and the distribution and improvement of fisheries management tools. It is hoped that these capabilities will enable fisheries scientists in ACP countries to actively contribute towards a discussion to solve common problems originating from the endangering of the ecological basis of their fisheries.