151
|
Feehan CJ, Grace SP, Narvaez CA. Ecological feedbacks stabilize a turf-dominated ecosystem at the southern extent of kelp forests in the Northwest Atlantic. Sci Rep 2019; 9:7078. [PMID: 31068664 PMCID: PMC6506546 DOI: 10.1038/s41598-019-43536-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 04/26/2019] [Indexed: 11/09/2022] Open
Abstract
Temperate marine ecosystems globally are undergoing regime shifts from dominance by habitat-forming kelps to dominance by opportunistic algal turfs. While the environmental drivers of shifts to turf are generally well-documented, the feedback mechanisms that stabilize novel turf-dominated ecosystems remain poorly resolved. Here, we document a decline of kelp Saccharina latissima between 1980 and 2018 at sites at the southernmost extent of kelp forests in the Northwest Atlantic and their replacement by algal turf. We examined the drivers of a shift to turf and feedback mechanisms that stabilize turf reefs. Kelp replacement by turf was linked to a significant multi-decadal increase in sea temperature above an upper thermal threshold for kelp survival. In the turf-dominated ecosystem, 45% of S. latissima were attached to algal turf rather than rocky substrate due to preemption of space. Turf-attached kelp required significantly (2 to 4 times) less force to detach from the substrate, with an attendant pattern of lower survival following 2 major wave events as compared to rock-attached kelp. Turf-attached kelp allocated a significantly greater percentage of their biomass to the anchoring structure (holdfast), with a consequent energetic trade-off of slower growth. The results indicate a shift in community dominance from kelp to turf driven by thermal stress and stabilized by ecological feedbacks of lower survival and slower growth of kelp recruited to turf.
Collapse
Affiliation(s)
- Colette J Feehan
- Department of Biology, Montclair State University, Montclair, NJ, 07043, USA.
| | - Sean P Grace
- Department of Biology and Werth Center for Coastal and Marine Studies, Southern Connecticut State University, New Haven, CT, 06515, USA
| | - Carla A Narvaez
- Department of Biology, Villanova University, Villanova, PA, 19085, USA
| |
Collapse
|
152
|
Climate change impacts on marine ecosystems through the lens of the size spectrum. Emerg Top Life Sci 2019; 3:233-243. [PMID: 33523153 PMCID: PMC7289007 DOI: 10.1042/etls20190042] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 04/16/2019] [Accepted: 04/17/2019] [Indexed: 11/17/2022]
Abstract
Climate change is a complex global issue that is driving countless shifts in the structure and function of marine ecosystems. To better understand these shifts, many processes need to be considered, yet they are often approached from incompatible perspectives. This article reviews one relatively simple, integrated perspective: the abundance-size spectrum. We introduce the topic with a brief review of some of the ways climate change is expected to impact the marine ecosystem according to complex numerical models while acknowledging the limits to understanding posed by complex models. We then review how the size spectrum offers a simple conceptual alternative, given its regular power law size-frequency distribution when viewed on sufficiently broad scales. We further explore how anticipated physical aspects of climate change might manifest themselves through changes in the elevation, slope and regularity of the size spectrum, exposing mechanistic questions about integrated ecosystem structure, as well as how organism physiology and ecological interactions respond to multiple climatic stressors. Despite its application by ecosystem modellers and fisheries scientists, the size spectrum perspective is not widely used as a tool for monitoring ecosystem adaptation to climate change, providing a major opportunity for further research.
Collapse
|
153
|
Schiel DR. Experimental analyses of diversity partitioning in southern hemisphere algal communities. Oecologia 2019; 190:179-193. [DOI: 10.1007/s00442-019-04375-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 02/26/2019] [Indexed: 11/25/2022]
|
154
|
Communities and Attachment Networks Associated with Primary, Secondary and Alternative Foundation Species; A Case Study of Stressed and Disturbed Stands of Southern Bull Kelp. DIVERSITY-BASEL 2019. [DOI: 10.3390/d11040056] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Southern bull kelps (Durvillaea spp., Fucales) are ‘primary’ foundation species that control community structures and ecosystem functions on temperate wave-exposed rocky reefs. However, these large foundation species are threatened by disturbances and stressors, including invasive species, sedimentation and heatwaves. It is unknown whether ‘alternative’ foundation species can replace lost southern bull kelps and its associated communities and networks. We compared community structure (by quantifying abundances of different species) and attachment-interaction networks (by quantifying which species were attached to other species) among plots dominated by Durvillaea spp. and plots where Durvillaea spp. were lost either through long-term repeated experimental removals or by recent stress from a marine heatwave. Long-term experimental removal plots were dominated by ‘alternative’ foundation species, the canopy-forming Cystophora spp. (Fucales), whereas the recent heatwave stressed plots were dominated by the invasive kelp Undaria pinnatifida (Laminariales). A network analysis of attachment interactions showed that communities differed among plots dominated by either Durvillaea spp., Cystophora spp. or U. pinnatifida, with different relationships between the primary, or alternative, foundation species and attached epiphytic ‘secondary’ foundation species. For example, native Cystophora spp. were more important as hosts for secondary foundation species compared to Durvillaea spp. and U. pinnatifida. Instead, Durvillaea spp. facilitated encrusting algae, which in turn provided habitat for gastropods. We conclude that (a) repeated disturbances and strong stressors can reveal ecological differences between primary and alternative foundation species, (b) analyses of abundances and attachment-networks are supplementary methods to identify linkages between primary, alternative and secondary foundation species, and (c) interspersed habitats dominated by different types of foundation species increase system-level biodiversity by supporting different species-abundance patterns and species-attachment networks.
Collapse
|
155
|
Smale DA, Epstein G, Parry M, Attrill MJ. Spatiotemporal variability in the structure of seagrass meadows and associated macrofaunal assemblages in southwest England (UK): Using citizen science to benchmark ecological pattern. Ecol Evol 2019; 9:3958-3972. [PMID: 31015980 PMCID: PMC6467847 DOI: 10.1002/ece3.5025] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 02/08/2019] [Accepted: 02/11/2019] [Indexed: 11/20/2022] Open
Abstract
Seagrass meadows underpin a variety of ecosystem services and are recognized as globally important habitats and a conservation priority. However, seagrass populations are currently impacted by a range of biotic and abiotic stressors, and many are in decline globally. As such, improved understanding of seagrass populations and their associated faunal assemblages is needed to better detect and predict changes in the structure and functioning of these key habitats. Here, we analyzed a large dataset-collected by recreational scuba divers volunteering on a citizen science project-to examine spatiotemporal patterns in ecological structure and to provide a robust and reliable baseline against which to detect future change. Seagrass (Zostera marina) shoot density and the abundance of associated faunal groups were quantified across 2 years at 19 sites nested within three locations in southwest UK, by collecting in situ quadrat samples (2,518 in total) during 328 dives. Seagrass shoot density and meadow fragmentation was comparable across locations but was highly variable among sites. Faunal abundance and assemblage structure varied between areas with or without seagrass shoots; this pattern was largely consistent between locations and years. Overall, increased seagrass density was related to increased faunal abundance and explained shifts in faunal assemblage structure, although individual faunal groups were affected differently. More broadly, our study shows that well-funded and orchestrated citizen science projects can, to some extent, gather fundamental information needed to benchmark ecological structure in poorly studied nearshore marine habitats.
Collapse
Affiliation(s)
- Dan A. Smale
- Marine Biological Association of the United Kingdom, The LaboratoryPlymouthUK
| | - Graham Epstein
- Marine Biological Association of the United Kingdom, The LaboratoryPlymouthUK
- Ocean and Earth Science, National Oceanography Centre SouthamptonUniversity of SouthamptonSouthamptonUK
| | | | - Martin J. Attrill
- School of Biological and Marine SciencesUniversity of PlymouthPlymouthUK
| |
Collapse
|
156
|
Starko S, Bailey LA, Creviston E, James KA, Warren A, Brophy MK, Danasel A, Fass MP, Townsend JA, Neufeld CJ. Environmental heterogeneity mediates scale-dependent declines in kelp diversity on intertidal rocky shores. PLoS One 2019; 14:e0213191. [PMID: 30913219 PMCID: PMC6435185 DOI: 10.1371/journal.pone.0213191] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 02/16/2019] [Indexed: 11/18/2022] Open
Abstract
Biodiversity loss is driven by interacting factors operating at different spatial scales. Yet, there remains uncertainty as to how fine-scale environmental conditions mediate biological responses to broad-scale stressors. We surveyed intertidal rocky shore kelp beds situated across a local gradient of wave action and evaluated changes in kelp diversity and abundance after more than two decades of broad scale stressors, most notably the 2013-2016 heat wave. Across all sites, species were less abundant on average in 2017 and 2018 than during 1993-1995 but changes in kelp diversity were dependent on wave exposure, with wave exposed habitats remaining stable and wave sheltered habitats experiencing near complete losses of kelp diversity. In this way, wave exposed sites have acted as refugia, maintaining regional kelp diversity despite widespread local declines. Fucoids, seagrasses and two stress-tolerant kelp species (Saccharina sessilis, Egregia menziesii) did not decline as observed in other kelps, and the invasive species Sargassum muticum increased significantly at wave sheltered sites. Long-term monitoring data from a centrally-located moderate site suggest that kelp communities were negatively impacted by the recent heatwave which may have driven observed losses throughout the region. Wave-sheltered shores, which saw the largest declines, are a very common habitat type in the Northeast Pacific and may be especially sensitive to losses in kelp diversity and abundance, with potential consequences for coastal productivity. Our findings highlight the importance of fine-scale environmental heterogeneity in mediating biological responses and demonstrate how incorporating differences between habitat patches can be essential to capturing scale-dependent biodiversity loss across the landscape.
Collapse
Affiliation(s)
- Samuel Starko
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
| | - Lauren A. Bailey
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Elandra Creviston
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Katelyn A. James
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
| | - Alison Warren
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
- Department of Biology, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Megan K. Brophy
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
| | - Andreea Danasel
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Megan P. Fass
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - James A. Townsend
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | | |
Collapse
|
157
|
Vergés A, McCosker E, Mayer‐Pinto M, Coleman MA, Wernberg T, Ainsworth T, Steinberg PD. Tropicalisation of temperate reefs: Implications for ecosystem functions and management actions. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13310] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Adriana Vergés
- Centre for Marine Science & Innovation and Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences UNSW Australia Sydney New South Wales Australia
- Sydney Institute of Marine Science Mosman New South Wales Australia
| | - Erin McCosker
- Centre for Marine Science & Innovation and Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences UNSW Australia Sydney New South Wales Australia
- Sydney Institute of Marine Science Mosman New South Wales Australia
| | - Mariana Mayer‐Pinto
- Centre for Marine Science & Innovation and Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences UNSW Australia Sydney New South Wales Australia
- Sydney Institute of Marine Science Mosman New South Wales Australia
| | - Melinda A. Coleman
- Department of Primary Industries New South Wales Fisheries Coffs Harbour, New South Wales Australia
- National Marine Science Centre, Southern Cross University Coffs Harbour, New South Wales Australia
| | - Thomas Wernberg
- School of Biological Sciences, UWA Oceans Institute University of Western Australia Crawley Western Australia Australia
- Department of Science and Environment (DSE) Roskilde University Roskilde Denmark
| | - Tracy Ainsworth
- Centre for Marine Science & Innovation and Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences UNSW Australia Sydney New South Wales Australia
- Sydney Institute of Marine Science Mosman New South Wales Australia
| | - Peter D. Steinberg
- Centre for Marine Science & Innovation and Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences UNSW Australia Sydney New South Wales Australia
- Sydney Institute of Marine Science Mosman New South Wales Australia
- Singapore Centre for Environmental Life Sciences Engineering Nanyang Technical University Singapore City Singapore
| |
Collapse
|
158
|
Genetic heterogeneity of two bioeconomically important kelp species along the Norwegian coast. CONSERV GENET 2019. [DOI: 10.1007/s10592-019-01162-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
159
|
Christie H, Gundersen H, Rinde E, Filbee‐Dexter K, Norderhaug KM, Pedersen T, Bekkby T, Gitmark JK, Fagerli CW. Can multitrophic interactions and ocean warming influence large-scale kelp recovery? Ecol Evol 2019; 9:2847-2862. [PMID: 30891221 PMCID: PMC6405503 DOI: 10.1002/ece3.4963] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 12/05/2018] [Accepted: 01/08/2019] [Indexed: 11/07/2022] Open
Abstract
Ongoing changes along the northeastern Atlantic coastline provide an opportunity to explore the influence of climate change and multitrophic interactions on the recovery of kelp. Here, vast areas of sea urchin-dominated barren grounds have shifted back to kelp forests, in parallel with changes in sea temperature and predator abundances. We have compiled data from studies covering more than 1,500-km coastline in northern Norway. The dataset has been used to identify regional patterns in kelp recovery and sea urchin recruitment, and to relate these to abiotic and biotic factors, including structurally complex substrates functioning as refuge for sea urchins. The study area covers a latitudinal gradient of temperature and different levels of predator pressure from the edible crab (Cancer pagurus) and the red king crab (Paralithodes camtschaticus). The population development of these two sea urchin predators and a possible predator on crabs, the coastal cod (Gadus morhua), were analyzed. In the southernmost and warmest region, kelp forests recovery and sea urchin recruitment are mainly low, although sea urchins might also be locally abundant. Further north, sea urchin barrens still dominate, and juvenile sea urchin densities are high. In the northernmost and cold region, kelp forests are recovering, despite high recruitment and densities of sea urchins. Here, sea urchins were found only in refuge habitats, whereas kelp recovery occurred mainly on open bedrock. The ocean warming, the increase in the abundance of edible crab in the south, and the increase in invasive red king crab in the north may explain the observed changes in kelp recovery and sea urchin distribution. The expansion of both crab species coincided with a population decline in the top-predator coastal cod. The role of key species (sea urchins, kelp, cod, and crabs) and processes involved in structuring the community are hypothesized in a conceptual model, and the knowledge behind the suggested links and interactions is explored.
Collapse
Affiliation(s)
| | | | - Eli Rinde
- Norwegian Institute for Water ResearchOsloNorway
| | | | - Kjell Magnus Norderhaug
- Department of BiologyUniversity of OsloOsloNorway
- Institute of Marine Research, FlødevigenHisNorway
| | - Torstein Pedersen
- Department of Arctic and Marine BiologyArctic University of NorwayTromsøNorway
| | - Trine Bekkby
- Norwegian Institute for Water ResearchOsloNorway
| | | | | |
Collapse
|
160
|
Sogn Andersen G, Moy FE, Christie H. In a squeeze: Epibiosis may affect the distribution of kelp forests. Ecol Evol 2019; 9:2883-2897. [PMID: 30891223 PMCID: PMC6405913 DOI: 10.1002/ece3.4967] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 10/09/2018] [Accepted: 11/12/2018] [Indexed: 11/06/2022] Open
Abstract
The processes limiting the population recovery of the kelp Saccharina latissima after recent large-scale loss from the south coast of Norway are poorly understood. Previous investigations do, however, suggest that the impacts of biotic interactions (epibiosis and competition) and increased water turbidity are important. We investigated the depth-related patterns of growth, epibiosis, and mortality in two sample populations of kelp, from the south and the southwest coast of Norway. The investigations were performed over a period of seven months, in a crossed translocational study, where kelps were mounted on rigs at six depths (1, 3, 6, 9, 15, and 24 m). In a second experiment, the amounts of light blocked by different epibiont layers growing on the kelp frond were investigated. While growth decreased with depth in spring and summer, the kelp grew faster at 15 m than at shallower depths in fall. Survival was low both in shallow water and below 15 m depth. Epibionts covered the kelp growing at depths from 1 to 9 m, and the laboratory study showed that the coverage may have deprived the individuals of as much as 90% of the available light. Although the depth-related results we present apply-in the strictest sense-only to kelp translocated on rigs, we argue that the relative patterns are relevant for natural populations. Growth and survival of S. latissima is likely to be reduced by heavy loads of epibionts, while depths where epibionts are sparse may be close to the lower limit of the kelps depth distribution along the south coast of Norway. This suggests that a vertical squeeze, or narrowing of the distribution range of kelp forests may be occurring in Norway.
Collapse
Affiliation(s)
- Guri Sogn Andersen
- Department of BiosciencesUniversity of OsloOsloNorway
- Norwegian Institute for Water ResearchOsloNorway
| | | | | |
Collapse
|
161
|
Reeves SE, Kriegisch N, Johnson CR, Ling SD. Reduced resistance to sediment-trapping turfs with decline of native kelp and establishment of an exotic kelp. Oecologia 2018; 188:1239-1251. [PMID: 30406820 DOI: 10.1007/s00442-018-4275-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 10/14/2018] [Indexed: 10/27/2022]
Abstract
Understanding the strength and type of interactions among species is vital to anticipate how ecosystems will respond to ongoing anthropogenic stressors. Here, we examine the ecological function of native (Ecklonia radiata) and invasive (Undaria pinnatifida) kelps in resisting shifts to sediment-trapping turf on reefs within the highly urbanized temperate Port Phillip Bay (PPB), Australia. Short-term (30 days) and long-term (232 days) manipulations demonstrated that kelp laminae can clear and maintain the substratum free of turfs, while conversely, removal of kelp leads to a proliferation of turfs. Analyses looking at the relationship between total length of E. radiata and U. pinnatifida and the area cleared of turf algae showed that the clearing effect of E. radiata over a year was greater than that of U. pinnatifida due to the annual die-back of the invasive. A natural experiment (608 days) identified that ongoing sea urchin (Heliocidaris erythrogramma) grazing led to native kelp bed decline, facilitating turf dominance. Even though U. pinnatifida establishes once native beds are disturbed, its ecological function in clearing turf is weaker than E. radiata, given its annual habit. In PPB, turfs represent the more persistent and problematic algal group and are likely changing the structure, function, and energy flows of shallow temperate reefs in this urbanised embayment.
Collapse
Affiliation(s)
- S E Reeves
- Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Hobart, TAS, 7004, Australia.
| | - N Kriegisch
- Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Hobart, TAS, 7004, Australia
| | - C R Johnson
- Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Hobart, TAS, 7004, Australia
| | - S D Ling
- Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Hobart, TAS, 7004, Australia
| |
Collapse
|
162
|
Wernberg T, Filbee-Dexter K. Grazers extend blue carbon transfer by slowing sinking speeds of kelp detritus. Sci Rep 2018; 8:17180. [PMID: 30464260 PMCID: PMC6249265 DOI: 10.1038/s41598-018-34721-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/24/2018] [Indexed: 11/08/2022] Open
Abstract
Marine plant communities such as kelp forests produce significant amounts of detritus, most of which is exported to areas where it can constitute an important trophic subsidy or potentially be sequestered in marine sediments. Knowing the vertical transport speed of detrital particles is critical to understanding the potential magnitude and spatial extent of these linkages. We measured sinking speeds for Laminaria hyperborea detritus ranging from whole plants to small fragments and sea urchin faecal pellets, capturing the entire range of particulate organic matter produced by kelp forests. Under typical current conditions, we determined that this organic material can be transported 10 s of m to 10 s of km. We show how the conversion of kelp fragments to sea urchin faeces, one of the most pervasive processes in kelp forests globally, increases the dispersal potential of detritus by 1 to 2 orders of magnitude. Kelp detritus sinking speeds were also faster than equivalent phytoplankton, highlighting its potential for rapid delivery of carbon to deep areas. Our findings support arguments for a significant contribution from kelp forests to subsidizing deep sea communities and the global carbon sink.
Collapse
Affiliation(s)
- Thomas Wernberg
- UWA Oceans Institute & School of Biological Sciences, University of Western Australia, Perth, Australia.
- Department of Science and Environment, Roskilde University, Roskilde, Denmark.
| | - Karen Filbee-Dexter
- Norwegian Institute for Water Research, Oslo, Norway
- Institute of Marine Research, Flødevigen, Norway
| |
Collapse
|
163
|
Biodiversity of Kelp Forests and Coralline Algae Habitats in Southwestern Greenland. DIVERSITY-BASEL 2018. [DOI: 10.3390/d10040117] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
All marine communities in Greenland are experiencing rapid environmental change, and to understand the effects on those structured by seaweeds, baseline records are vital. The kelp and coralline algae habitats along Greenland’s coastlines are rarely studied, and we fill this knowledge gap for the area around Nuuk, west Greenland. Using subtidal swath surveys, photo-quadrats, and grab samples, we characterised the diversity of floral and faunal assemblages in kelp forests and coralline algae beds. The most abundant herbivore assemblages and the most diverse communities occur in the interstitial habitats of rhodolith beds. In kelp forests, species diversity is higher in epi-benthic (photo-quadrat) and mid-water (swath) surveys. These habitats are not mutually exclusive; Agarum clathratum is prominent in coralline algal habitats, while crustose coralline algae cover the bedrock under kelp holdfasts. Overall, the suite of surveys used capture the diverse communities within kelp forests and coralline algae in Greenland and their differing role in the life history of the inhabitants. Furthermore, coralline algae beds are an important carbonate store, with CaCO3 concentrations ranging from 28.06 to 103.73 g·m−3. Our research sets the baseline for continued investigations and monitoring of these important habitats and their supported fisheries.
Collapse
|
164
|
Raven J. Blue carbon: past, present and future, with emphasis on macroalgae. Biol Lett 2018; 14:rsbl.2018.0336. [PMID: 30282745 DOI: 10.1098/rsbl.2018.0336] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 09/04/2018] [Indexed: 11/12/2022] Open
Abstract
Blue carbon did not originally include macroalgal ecosystems; however evidence is mounting that macroalgal ecosystems function in marine carbon sequestration. The great majority of present day marine macroalgal net primary productivity (NPP) involves haptophytic algae on eroding shores. For these organisms the long-term storage of particulate organic carbon involves export from the site of production of biomass that has evaded parasites and grazers, and that some of the exported biomass is sedimented and stored rather than being mineralized en route by detritivores (microbes and fauna). Export from eroding shores, and subsequent storage, of haptophytic marine macroalgal particulate organic carbon could have started by 1.6 Ga. Storage on depositing shores close to the site of NPP by rhizophytic macroalgae and then by rhizophytic coastal seagrasses, tidal marshes and mangroves began not less than 209 Ma ago. Future increases in surface ocean temperatures may bring tropical marine macroalgae to their upper temperature limit, while temperate marine macroalgae will migrate poleward, in both cases assuming that temperature increases faster than genetic adaptation to higher temperature. Increased CO2 in the surface ocean will generally favour uncalcified over calcified marine macroalgae. This results in decreased CO2 release from decreased calcification, as well as decreased ballasting by CaCO3 of exported particulate organic carbon resulting in decreasing sedimentation. While much more work is needed, the available information suggests that macroalgae play a significant role in marine organic carbon storage.
Collapse
Affiliation(s)
- John Raven
- Division of Plant Science, University of Dundee at the James Hutton Institute, Invergowrie, Dundee DD2 5DQ, UK .,Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| |
Collapse
|
165
|
Martínez B, Radford B, Thomsen MS, Connell SD, Carreño F, Bradshaw CJA, Fordham DA, Russell BD, Gurgel CFD, Wernberg T. Distribution models predict large contractions of habitat-forming seaweeds in response to ocean warming. DIVERS DISTRIB 2018. [DOI: 10.1111/ddi.12767] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Affiliation(s)
- Brezo Martínez
- Departamento de Biología y Geología; Universidad Rey Juan Carlos; Móstoles Spain
| | - Ben Radford
- Australian Institute of Marine Science; Crawley WA Australia
| | - Mads S. Thomsen
- UWA Oceans Institute and School of Biological Sciences; The University of Western Australia; Crawley WA Australia
- Marine Ecology Research Group; School of Biological Sciences; University of Canterbury; Christchurch New Zealand
| | - Sean D. Connell
- Southern Seas Ecology Laboratories; DP418; School of Earth and Environmental Sciences; The University of Adelaide; Adelaide SA Australia
| | - Francisco Carreño
- Departamento de Biología y Geología; Universidad Rey Juan Carlos; Móstoles Spain
| | - Corey J. A. Bradshaw
- Global Ecology; College of Science and Engineering; Flinders University; Adelaide SA Australia
| | - Damien A. Fordham
- School of Earth and Environmental Sciences; The University of Adelaide; Adelaide SA Australia
| | - Bayden D. Russell
- The Swire Institute of Marine Science; School of Biological Sciences; The University of Hong Kong; Hong Kong Hong Kong
| | - C. Frederico D. Gurgel
- School of Earth and Environmental Sciences; The University of Adelaide; Adelaide SA Australia
- Department of Environment, Water and Natural Resources; State Herbarium of South Australia; Kent Town SA Australia
- South Australian Research and Development Institute; Aquatic Sciences; Henley Beach SA Australia
| | - Thomas Wernberg
- UWA Oceans Institute and School of Biological Sciences; The University of Western Australia; Crawley WA Australia
- Department of Science and Environment; Roskilde University; Roskilde Denmark
| |
Collapse
|
166
|
Pessarrodona A, Moore PJ, Sayer MDJ, Smale DA. Carbon assimilation and transfer through kelp forests in the NE Atlantic is diminished under a warmer ocean climate. GLOBAL CHANGE BIOLOGY 2018; 24:4386-4398. [PMID: 29862600 PMCID: PMC6120504 DOI: 10.1111/gcb.14303] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 04/19/2018] [Accepted: 04/27/2018] [Indexed: 05/20/2023]
Abstract
Global climate change is affecting carbon cycling by driving changes in primary productivity and rates of carbon fixation, release and storage within Earth's vegetated systems. There is, however, limited understanding of how carbon flow between donor and recipient habitats will respond to climatic changes. Macroalgal-dominated habitats, such as kelp forests, are gaining recognition as important carbon donors within coastal carbon cycles, yet rates of carbon assimilation and transfer through these habitats are poorly resolved. Here, we investigated the likely impacts of ocean warming on coastal carbon cycling by quantifying rates of carbon assimilation and transfer in Laminaria hyperborea kelp forests-one of the most extensive coastal vegetated habitat types in the NE Atlantic-along a latitudinal temperature gradient. Kelp forests within warm climatic regimes assimilated, on average, more than three times less carbon and donated less than half the amount of particulate carbon compared to those from cold regimes. These patterns were not related to variability in other environmental parameters. Across their wider geographical distribution, plants exhibited reduced sizes toward their warm-water equatorward range edge, further suggesting that carbon flow is reduced under warmer climates. Overall, we estimated that Laminaria hyperborea forests stored ~11.49 Tg C in living biomass and released particulate carbon at a rate of ~5.71 Tg C year-1 . This estimated flow of carbon was markedly higher than reported values for most other marine and terrestrial vegetated habitat types in Europe. Together, our observations suggest that continued warming will diminish the amount of carbon that is assimilated and transported through temperate kelp forests in NE Atlantic, with potential consequences for the coastal carbon cycle. Our findings underline the need to consider climate-driven changes in the capacity of ecosystems to fix and donate carbon when assessing the impacts of climate change on carbon cycling.
Collapse
Affiliation(s)
- Albert Pessarrodona
- The Citadel Hill LaboratoryMarine Biological Association of the United KingdomPlymouthUK
- Present address:
UWA Oceans Institute and School of Biological SciencesUniversity of Western AustraliaCrawleyWAAustralia
| | - Pippa J. Moore
- Institute of Biological, Environmental and Rural SciencesAberystwyth UniversityAberystwythUK
- Centre for Marine Ecosystems ResearchSchool of Natural SciencesEdith Cowan UniversityJoondalupWAAustralia
| | - Martin D. J. Sayer
- NERC National Facility for Scientific DivingScottish Association for Marine ScienceObanUK
| | - Dan A. Smale
- The Citadel Hill LaboratoryMarine Biological Association of the United KingdomPlymouthUK
| |
Collapse
|
167
|
Maggi E, Puccinelli E, Benedetti-Cecchi L. Ecological feedback mechanisms and variable disturbance regimes: the uncertain future of Mediterranean macroalgal forests. MARINE ENVIRONMENTAL RESEARCH 2018; 140:342-357. [PMID: 30017202 DOI: 10.1016/j.marenvres.2018.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 07/08/2018] [Accepted: 07/08/2018] [Indexed: 06/08/2023]
Abstract
Loss of algal canopies can result in a shift towards a turf-dominated state, where variability in species life-history traits can determine new mechanisms of feedback, and influence the degraded system under variable regimes of disturbance. By focusing on rockpools dominated by Cystoseira brachycarpa, we tested the hypothesis that the alga Dictyopteris polypodioides could take advantage of extreme regimes of disturbance related to storms, and outcompete other turfs through a distinctive combination of life traits. Replacement of the canopy was initially driven by a mix of taxon-specific life-traits and resulting assemblages were susceptible to intense events of disturbance. Subsequently, D. polypodioides dominated removal quadrats, favored by density-dependent abilities to intercept more light and reach larger size than the rest of turf. These new positive feedbacks may contribute to maintain the modified state of the system and influence its ability to withstand extreme abiotic conditions.
Collapse
Affiliation(s)
- E Maggi
- Dipartimento di Biologia, CoNISMa, Università di Pisa, Italy.
| | - E Puccinelli
- Oceanography Department, Marine Research Institute, University of Cape Town, South Africa
| | | |
Collapse
|
168
|
Teagle H, Smale DA. Climate-driven substitution of habitat-forming species leads to reduced biodiversity within a temperate marine community. DIVERS DISTRIB 2018. [DOI: 10.1111/ddi.12775] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Affiliation(s)
- Harry Teagle
- The Laboratory; Marine Biological Association of the United Kingdom; Plymouth UK
- University of Southampton; Southampton UK
| | - Dan A. Smale
- The Laboratory; Marine Biological Association of the United Kingdom; Plymouth UK
| |
Collapse
|