Abstract Offshore wind farms (OWFs) are proliferating globally across marine ecosystems. We argue that alongside traditional avoidance, mitigation, compensation, and offsetting measures to reduce project-level OWF impacts, allocating a small percentage of OWF investments to marine restoration as a licensing fee for using marine space would catalyze large-scale marine restoration. This involves establishing large marine-protected areas and implementing active ecosystem restoration to help recover key habitats and species. Allocating just 1%–5% of the projected US$6 trillion global offshore wind farm investments by 2050 to marine conservation and restoration could have a powerful impact, creating a historic opportunity to achieve biodiversity goals on time.
Abstract In this article, we review evidence of how climate change has already resulted in clearly discernable changes in marine Arctic ecosystems. After defining the term ‘footprint’ and evaluating the availability of reliable baseline information we review the published literature to synthesize the footprints of climate change impacts in marine Arctic ecosystems reported as of mid‐2009. We found a total of 51 reports of documented changes in Arctic marine biota in response to climate change. Among the responses evaluated were range shifts and changes in abundance, growth/condition, behaviour/phenology and community/regime shifts. Most reports concerned marine mammals, particularly polar bears, and fish. The number of well‐documented changes in planktonic and benthic systems was surprisingly low. Evident losses of endemic species in the Arctic Ocean, and in ice algae production and associated community remained difficult to evaluate due to the lack of quantitative reports of its abundance and distribution. Very few footprints of climate change were reported in the literature from regions such as the wide Siberian shelf and the central Arctic Ocean due to the limited research effort made in these ecosystems. Despite the alarming nature of warming and its strong potential effects in the Arctic Ocean the research effort evaluating the impacts of climate change in this region is rather limited.
Major aggregations of nesting green turtles ( Chelonia mydas ) occur in the northern Red Sea, although little is known about the reproductive ecology of this endangered species in the region. To address this issue, we satellite-tracked 30 female green turtles to document their movements and to identify factors driving habitat use at two major rookeries in the Red Sea, Jazirat Mashabah (Mashabah Island) and Ras Al Baridi in Saudi Arabia. Between successive nesting events, turtles displayed high fidelity to nesting beaches and adjacent in-water habitats (inter-nesting habitats). Using generalized linear mixed models, we estimated the mean probability of nesting per beach emergence (nesting success rate) to be 0.628, and the mean duration between a successful nesting event and the successive emergence onto the beach (re-nesting interval) to be 10.8 days at each site. The nesting success rate was relatively high (>0.8) when the preceding daytime land surface temperature (LST) was lower than 37°C but decreased with elevated daytime LST (<0.4 when >47°C). Re-nesting interval was longer at lower water temperatures and towards the end of the nesting season of individuals. Our study improves the robustness of abundance estimates from census data (e.g., track counts) and shows that the protection of nesting and inter-nesting habitats during a breeding season would be an effective conservation strategy for the species. We discuss how global warming could increase energy expenditure due to lowered nesting success, ultimately compromising the reproductive fitness of these populations.
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 614:79-90 (2019) - DOI: https://doi.org/10.3354/meps12912 Thermal dependence of seagrass ecosystem metabolism in the Red Sea Celina Burkholz, Carlos M. Duarte, Neus Garcias-Bonet* Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia *Corresponding author: neus.garciasbonet@kaust.edu.sa ABSTRACT: The Red Sea is one of the warmest seas with shallow seagrass ecosystems exposed to extreme temperatures, in excess of 35°C, during the summer months. Seagrass meadows are net autotrophic ecosystems, but respiration increases faster than primary production with temperature. This may lead to a shift from an autotrophic to a heterotrophic system at the highest temperatures. Although tropical seagrasses are adapted to high temperatures, the metabolic rates of Red Sea seagrasses have not yet been reported. Here we assessed the community metabolism of 2 seagrass ecosystems, an Enhalus acoroides monospecific meadow and a Cymodocea serrulata and Halodule uninervis mixed meadow, located in the central Red Sea. We measured in situ net community production (NCP), community respiration (R), gross primary production (GPP), activation energy and community production-irradiance curves along their natural temperature gradient over 1 yr by measuring diel fluctuations in dissolved oxygen. The results were species-specific; while the monospecific meadow was autotrophic throughout the year (annual weighted average NCP: 64.63 ± 11.89 mmol O2 m-2 d-1, GPP:R ratio: 1.42 ± 0.06), the mixed meadow was heterotrophic during the summer months (annual weighted average NCP: -4.15 ± 9.39 mmol O2 m-2 d-1, GPP:R: 1.04 ± 0.05). In both seagrass meadows, R and GPP increased with increasing temperature, but differences in activation energies indicated that the mixed meadow is more sensitive to increasing seawater temperatures. These findings suggest contrasting responses in tropical seagrass species to rising temperature, pointing out the potential vulnerability of seagrasses to ocean warming in the Red Sea. KEY WORDS: Seagrass ecosystems · Community metabolism · Thermal dependence · Activation energy · PI curves · Red Sea Full text in pdf format Supplementary material PreviousNextCite this article as: Burkholz C, Duarte CM, Garcias-Bonet N (2019) Thermal dependence of seagrass ecosystem metabolism in the Red Sea. Mar Ecol Prog Ser 614:79-90. https://doi.org/10.3354/meps12912 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 614. Online publication date: April 04, 2019 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2019 Inter-Research.
A survey of the phytoplankton communities in 165 Florida lakes during 1980 indicated 27% of 308 samples collected had phytoplankton populations that were at or very close to their maximal achievable densities. This finding suggests that nonnutrient constraints including self-regulation by the algal community may be playing an important role in regulating phytoplankton biomass in many Florida lakes. Algal populations that were close to their maximal achievable densities had algal biomass values >10 mg liter−1 and Chl a concentrations >10 mg m−3. As nonnutrient constraints became more important, algal communities shifted from small-celled, diatom-green algal communities to communities dominated primarily by large, blue-green bacteria.
