Sea urchin grazing and kelp re-vegetation in the NE Atlantic

Norderhaug, Kjell Magnus; Christie, Hartvig

doi:10.1080/17451000902932985

Cited by 130 publications

(123 citation statements)

References 72 publications

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“…Nevertheless, several indicators indicated potentially degraded situations both in the coastal area and in the area of seasonal ice presence: (1) Along northern Norway coast, the current extent of kelp forest, an important component of fjords ecosystem and coastal landscape, cannot be considered as good in northern Norway. Kelp forests along the Norwegian and Russian coast were indeed dramatically grazed during the early 1970s and replaced by barren grounds dominated by sea urchins (Norderhaug and Christie, 2009). Though a progressive northward recovery of kelp forests extent is observed, its recovery status is still partial in northern Norway (Sivertsen, 2006;Rinde et al, 2014).…”

Section: Evaluation Of the Assessment Resultsmentioning

confidence: 99%

Indicator-Based Assessment of Marine Biological Diversity–Lessons from 10 Case Studies across the European Seas

Uusitalo

Blanchet

Andersen³

et al. 2016

Front. Mar. Sci.

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The Marine Strategy Framework Directive requires the environmental status of European marine waters to be assessed using biodiversity as 1 out of 11 descriptors, but the complexity of marine biodiversity and its large span across latitudinal and salinity gradients have been a challenge to the scientific community aiming to produce approaches for integrating information from a broad range of indicators. The Nested Environmental status Assessment Tool (NEAT), developed for the integrated assessment of the status of marine waters, was applied to 10 marine ecosystems to test its applicability and compare biodiversity assessments across the four European regional seas. We evaluate the assessment results as well as the assessment designs of the 10 cases, and how the assessment design, particularly the choices made regarding the area and indicator selection, affected the results. The results show that only 2 out of the 10 case study areas show more than 50% probability of being in good status in respect of biodiversity. No strong pattern among the ecosystem components across the case study areas could be detected, but marine mammals, birds, and benthic vegetation indicators tended to indicate poor status while zooplankton indicators indicated good status when included into the assessment. The analysis shows that the assessment design, including the selection of indicators, their target values, geographical resolution Uusitalo et al.Case-Studies of Marine Biodiversity and habitats to be assessed, has potentially a high impact on the result, and the assessment structure needs to be understood in order to make an informed assessment. Moreover, recommendations are provided for the best practice of using NEAT for marine status assessments.

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Section: Evaluation Of the Assessment Resultsmentioning

confidence: 99%

Indicator-Based Assessment of Marine Biological Diversity–Lessons from 10 Case Studies across the European Seas

Uusitalo

Blanchet

Andersen³

et al. 2016

Front. Mar. Sci.

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“…These altered states also have major impacts on the marine ecology of the area, affecting macroalgae-dominated rocky reefs (Ling 2008) and the important marine resources that they support (Pinnegar et al 2000, Shears & Babcock 2002. However, factors controlling urchin population size are still poorly understood (Norderhaug & Christie 2009, Uthicke et al 2009). …”

Section: Introductionmentioning

confidence: 99%

Effect of temperature on settlement and postsettlement survival in a barrens-forming sea urchin

Hernández¹,

Clemente²,

Girard³

et al. 2010

Mar. Ecol. Prog. Ser.

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Large populations of the sea urchin Diadema aff. antillarum occur in the east Atlantic archipelagos. The origin and stability of these large herbivorous populations are not well known. Variability in settlement, recruitment and adult urchin density were quantified and compared over a 7 yr period (2002 to 2008) within the Canary Islands. Variables that potentially affect urchin settlement such as gonad index, temperature and primary productivity (phytoplankton) were measured. Settlement was found to be high during warm years; temperatures > 24°C induced important settlement pulses. Postsettlement survival in barren areas of Tenerife was exponentially and positively correlated with seawater temperature changes, while very low to 0 survival was found at macroalgal beds off El Hierro. Assuming that climate change predictions are correct, the strong positive relationship between thermal history and postsettlement survival of this ecologically important species suggests that barren grounds will persist as seawater warms up if no mass mortality occurs. This future scenario will have important implications for the stability of algal beds and coastal ecosystems as a whole.KEY WORDS: Diadema aff. antillarum · Larval settlement · Seawater warming · Recruitment · Habitat Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 413: [69][70][71][72][73][74][75][76][77][78][79][80] 2010 eastern Canada; Scheibling 1986, Lauzon-Guay & Scheibling 2007.It is well known that temperature regulates larval development and higher temperatures facilitate faster larval growth (Thorson 1950, Hoegh-Guldberg & Pearse 1995 and urchin reproduction . Temperature has been considered an important causative factor in the destruction of macroalgal beds by sea urchin grazing (Hart & Scheibling 1988, Ling et al. 2008. However, in population ecology, it is not always easy to establish causative effects due to the lack of historical data or baseline studies. The link between sea surface temperature and destructive grazing due to the rapid development that urchin larvae experience in warmer waters seems an oversimplistic model that requires further study. This relationship may apply for some sea urchin species, but not for others in which recruitment is inversely related to high temperatures. For example, Strongylocentrotus purpuratus recruits around southern California are more abundant following cold winter episodes (Ebert 1983), and low temperatures seem to favour high recruitment of S. droebachiensis in the coast of Norway (Sivertsen 2006). In any case, understanding the influence of abiotic factors on urchin populations is necessary to predict the consequences of seawater warming that is associated with large-scale climate change. This is of particular interest in the study of population dynamics in thermophilous species such as Diadema aff. antillarum, which is particulary sensitive to water warming processes and is a key herbivore.The relevance of larval supply in regulating populations of me...

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“…Even though urchin barrens can be relatively dynamic and short-lived elements of the kelp forest ecosystem (Harrold andReed 1985, Graham 2004), globally they have been reported to persist for long periods on temperate reefs, in some cases for decades (Schiel 1990, Jackson 2001, Steneck et al 2002, Shears and Babcock 2003, Smith et al 2004, Norderhaug and Christie 2009. In some ecosystems, sea urchin consumption of kelp can be limited primarily by predation on urchins (Estes and Palmisano 1974, Dayton 1985, Edwards 2004.…”

Section: Introductionmentioning

confidence: 99%

Kelp forest habitat restoration has the potential to increase sea urchin gonad biomass

Claisse

Williams

Ford³

et al. 2013

Ecosphere

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Abstract. When taking an ecosystem-based approach to marine resource management, managers may be able to implement a combination of management tools in order to mitigate the socioeconomic impacts of implementing any one in isolation, while providing greater overall ecological benefits. The harvest of Strongylocentrotus franciscanus (red sea urchin) for their gonads is one of the most important commercial fisheries in California. However, in some locations, high densities of the unfished Strongylocentrotus purpuratus (purple sea urchin) can clear expanses of kelp forest resulting in ''urchin barrens.'' The lack of macroalgal food resources can result in reduced gonad production, making S. franciscanus within barrens less valuable to a fishery. We investigated the potential of kelp forest habitat restoration, which may be achievable primarily by removing S. purpuratus from barrens, to positively impact the local S. franciscanus fishery and offset the losses in fishing grounds within recently established MPAs in our study area. Generalized linear modeling of the relationship between gonad weight and length (test diameter) demonstrated clear size-specific differences in gonad production between urchins collected in barrens and kelp forests. These relationships varied over time, with the maximum observed mean gonad biomass at length being 484% greater in kelp forest than barren habitat for S. franciscanus just above the legal size limit. The variability in S. franciscanus density (5.2 times greater in urchin barrens), size structure (mean test diameters were approximately 50% greater in kelp forest) and gonad production were then incorporated using Monte Carlo simulations. Results indicated that restoration could potentially result in an 864% increase in S. franciscanus gonad biomass available to the fishery, and a 132% increase in reproductive potential per unit area of urchin barren restored to kelp forest. If all 36 ha of urchin barren habitat mapped outside of the new MPAs in the study area were restored, the increase in gonad biomass available to the fishery could potentially offset 52% of which is now protected within the 109 ha of rocky reef in the new MPAs. Kelp restoration has the potential to play a valuable role as one of many integrated tools in an ecosystem-based management approach.

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Sea urchin grazing and kelp re-vegetation in the NE Atlantic

Cited by 130 publications

References 72 publications

Indicator-Based Assessment of Marine Biological Diversity–Lessons from 10 Case Studies across the European Seas

Indicator-Based Assessment of Marine Biological Diversity–Lessons from 10 Case Studies across the European Seas

Effect of temperature on settlement and postsettlement survival in a barrens-forming sea urchin

Kelp forest habitat restoration has the potential to increase sea urchin gonad biomass

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