combined with other conservation measures such as the exclusion of urchin predators from fishing and protection of algal stand ecosystems. Combining these
strategies would ensure that the ecosystem would keep the balance between
urchins and algae. Urchin removals alone are inadequate (but see Sect. 15.4). In
general, the management of urchin outbreak cases around the world has consisted
in urchin removal. However better results have been always obtained when this is
done inside a marine protected area (Tegner and Dayton 1977; McClanahan et al.
1996). This kind of management measures has been proposed for the Canary
Islands several times (Clemente 2007; Hernández et al. 2008a; Clemente et al.
2009; Clemente et al. 2011).
These combined actions would potentially decrease the frequency and duration
of urchin overgrazing but limited knowledge of direct and indirect effects of these
ecosystem scale actions makes it difficult to assess the applicability and sustainability of this method. Therefore we call for governmental responsibility and rigor
when planning this kind of action. Uncontrolled removal of urchins during the
planned fishery could cause urchin populations to ‘‘crash’’ with potential ecological and economic side effects. The recent ‘‘boom and bust’’ trend of sea urchin
fisheries around the word (USA, Mexico, Canada) (Andrew et al. 2002; Uthicke
et al. 2009), most of them considered nowadays as overexploited, indicates the
need for more information on basic population parameters of species when
implementing removal actions (Russell 2000). Rigorously evaluating population
demographics has, in the case of the species D. africana, both ecological and
economic significance, especially now that it is beginning to be commercially
harvested. We encourage seeking sustainable solutions to the increasing populations of the sea urchin D. africana, trying to contribute to the correct management
and conservation of the fragile marine resources of the Canary Islands. However,
we have to develop standards for the commercial exploitation of this species of
what we lack today.
15.6 Recomendations
We have divided our recommendations into three major sections: biodiversity,
ecology and fisheries. These constitute the main research lines that currently drive
research on echinoderms in the Canarian Institutions (universities and research
institutes). Moreover, in each section we have pointed out research gaps that
should be considered for future studies in the archipelago.Biodiversity
– Accurate information about spatial distribution of echinoderm fauna is needed
to precisely identify species habitats and depths ranges.
– Genetics studies of some taxonomic groups are needed to clarify biogeographical patterns and taxonomic identification problems (e.g. Arbaciella elegans is thought to be small Arbacia lixula).
15 Echinoderms of the Canary Islands, Spain
501
strategies would ensure that the ecosystem would keep the balance between
urchins and algae. Urchin removals alone are inadequate (but see Sect. 15.4). In
general, the management of urchin outbreak cases around the world has consisted
in urchin removal. However better results have been always obtained when this is
done inside a marine protected area (Tegner and Dayton 1977; McClanahan et al.
1996). This kind of management measures has been proposed for the Canary
Islands several times (Clemente 2007; Hernández et al. 2008a; Clemente et al.
2009; Clemente et al. 2011).
These combined actions would potentially decrease the frequency and duration
of urchin overgrazing but limited knowledge of direct and indirect effects of these
ecosystem scale actions makes it difficult to assess the applicability and sustainability of this method. Therefore we call for governmental responsibility and rigor
when planning this kind of action. Uncontrolled removal of urchins during the
planned fishery could cause urchin populations to ‘‘crash’’ with potential ecological and economic side effects. The recent ‘‘boom and bust’’ trend of sea urchin
fisheries around the word (USA, Mexico, Canada) (Andrew et al. 2002; Uthicke
et al. 2009), most of them considered nowadays as overexploited, indicates the
need for more information on basic population parameters of species when
implementing removal actions (Russell 2000). Rigorously evaluating population
demographics has, in the case of the species D. africana, both ecological and
economic significance, especially now that it is beginning to be commercially
harvested. We encourage seeking sustainable solutions to the increasing populations of the sea urchin D. africana, trying to contribute to the correct management
and conservation of the fragile marine resources of the Canary Islands. However,
we have to develop standards for the commercial exploitation of this species of
what we lack today.
15.6 Recomendations
We have divided our recommendations into three major sections: biodiversity,
ecology and fisheries. These constitute the main research lines that currently drive
research on echinoderms in the Canarian Institutions (universities and research
institutes). Moreover, in each section we have pointed out research gaps that
should be considered for future studies in the archipelago.Biodiversity
– Accurate information about spatial distribution of echinoderm fauna is needed
to precisely identify species habitats and depths ranges.
– Genetics studies of some taxonomic groups are needed to clarify biogeographical patterns and taxonomic identification problems (e.g. Arbaciella elegans is thought to be small Arbacia lixula).
15 Echinoderms of the Canary Islands, Spain
501