scholarly journals Ocean climate connectivity and the future range shifts of marine biodiversity.

Author(s):  
Panagiotis Petsas ◽  
Aggeliki Doxa ◽  
Vasiliki Almpanidou ◽  
Antonios D. Mazaris

Abstract Shifting distribution to track suitable climate is a potential strategy for marine species to cope with ocean warming. Yet, the ability of species to successfully reach future climate analogs largely depends on the length of the paths that connect them, and on the exposure of these paths to extreme climates during this transition. Here, we evaluate marine climate connectivity for trajectories between climatic analogs on a global scale. We find that while movement between climatic analogs is more intense in the northern seas of the planet, they require longer trajectories to reach climatic analogs, with high climatic exposure to extreme conditions. On the contrary, the southern seas host areas that have closer climatic analogs, further subjected to a lower exposure to dissimilar climates. These patterns are mirrored in the connectivity properties of the global marine protected areas, highlighting sites which might fail to facilitate connectivity to future climates. Our results suggest that potential shifts between climatic analogs might be subjected to more limitations than those suggested by previous studies, with marine connectivity offering novel insights for the establishment of climate-wise conservation future networks.

2021 ◽  
Author(s):  
Francesco Mugnai ◽  
Emese Meglécz ◽  
Federica Costantini ◽  

Marine biodiversity underpins ecosystem health and societal well-being. Preservation of biodiversity hotspots is a global challenge. Molecular tools, like DNA barcoding and metabarcoding, hold great potential for biodiversity monitoring, possibly outperforming more traditional taxonomic methods. However, metabarcoding-based biodiversity assessments are limited by the availability of sequences in barcoding reference databases; a lack thereof results in high percentages of unassigned sequences. In this study we (i) present the current status of known vs. barcoded marine species at a global scale based on online taxonomic and genetic databases; and (ii) compare the current status with data from ten years ago. Then we analyzed occurrence data of marine animal species from five Large Marine Ecosystems (LMEs) classified as biodiversity hotspots, to identify any consistent disparities in COI barcoding coverage between geographic regions and at phylum level. Barcoding coverage varied among LMEs (from 36.8% to 62.4% COI-barcoded species) and phyla (from 4.8% to 74.7% COI-barcoded species), with Porifera, Bryozoa and Platyhelminthes being highly underrepresented, compared to Chordata, Arthropoda and Mollusca. We demonstrate that although barcoded marine species increased from 9.5% to 14.2% since the last assessment in 2011, about 15,000 (corresponding to 7.8% increase) new species were described from 2011 to 2021. The next ten years will thus be crucial to enroll concrete collaborative measures and long term initiatives (e.g., Horizon 2030, Ocean Decade) to populate barcoding libraries for the marine realm.


2021 ◽  
Vol 118 (15) ◽  
pp. e2015094118
Author(s):  
Chhaya Chaudhary ◽  
Anthony J. Richardson ◽  
David S. Schoeman ◽  
Mark J. Costello

The latitudinal gradient in species richness, with more species in the tropics and richness declining with latitude, is widely known and has been assumed to be stable over recent centuries. We analyzed data on 48,661 marine animal species since 1955, accounting for sampling variation, to assess whether the global latitudinal gradient in species richness is being impacted by climate change. We confirm recent studies that show a slight dip in species richness at the equator. Moreover, richness across latitudinal bands was sensitive to temperature, reaching a plateau or declining above a mean annual sea surface temperature of 20 °C for most taxa. In response, since the 1970s, species richness has declined at the equator relative to an increase at midlatitudes and has shifted north in the northern hemisphere, particularly among pelagic species. This pattern is consistent with the hypothesis that climate change is impacting the latitudinal gradient in marine biodiversity at a global scale. The intensification of the dip in species richness at the equator, especially for pelagic species, suggests that it is already too warm there for some species to survive.


2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Beth A. Polidoro ◽  
Cristiane T. Elfes ◽  
Jonnell C. Sanciangco ◽  
Helen Pippard ◽  
Kent E. Carpenter

Given the economic and cultural dependence on the marine environment in Oceania and a rapidly expanding human population, many marine species populations are in decline and may be vulnerable to extinction from a number of local and regional threats. IUCN Red List assessments, a widely used system for quantifying threats to species and assessing species extinction risk, have been completed for 1190 marine species in Oceania to date, including all known species of corals, mangroves, seagrasses, sea snakes, marine mammals, sea birds, sea turtles, sharks, and rays present in Oceania, plus all species in five important perciform fish groups. Many of the species in these groups are threatened by the modification or destruction of coastal habitats, overfishing from direct or indirect exploitation, pollution, and other ecological or environmental changes associated with climate change. Spatial analyses of threatened species highlight priority areas for both site- and species-specific conservation action. Although increased knowledge and use of newly available IUCN Red List assessments for marine species can greatly improve conservation priorities for marine species in Oceania, many important fish groups are still in urgent need of assessment.


2021 ◽  
pp. 152450042110538
Author(s):  
Maïa Sarrouf Willson ◽  
Craig Turley ◽  
Lamees A. Daar ◽  
Hussein Al Masroori ◽  
Hussain Al Muscati ◽  
...  

Background Entanglement of marine species, particularly endangered sea turtles and cetaceans, in abandoned, lost or otherwise discarded fishing gear is a major conservation concern. Focus of the Article This case study applies Community-Based Social Marketing (CBSM) to reduce marine wildlife net entanglement in the waters surrounding Masirah Island, a marine biodiversity hotspot in Oman. Importance to the Social Marketing Field The study demonstrates the use of social marketing tools in biodiversity conservation, bringing new knowledge to the cross-application of these two fields. Methods The CBSM methodology was applied to select behaviours, identify barriers and benefits, develop strategies and design a pilot study. The responsible disposal of derelict nets in skip bins was selected as the target behaviour, and a mix of behavioural change tools was applied to achieve change: convenience (installation of three skip bins), education (installation of informative signs, distribution of awareness posters, one-to-one engagement with fishers on the beaches), prompts (installation of signs and posters on vessels) and social norms (one-to-one engagement with key influencers and decision makers). The monitoring of behaviour change took place through structured observations over 23 weeks, focussing on the number of nets disposed of in the allocated skip bins. Results Results showed a low level of behaviour adoption rate by skiff and launch vessel fisheries, respectively, 5.36% and 2.58%. Positive results were observed for a short time but did not reach the estimated target value throughout the study period. Recommendations for Research Our pilot study did not lead to broad-scale implementation and we recommend further awareness and engagement with the target audience, trials of various behaviour change tools and increase field monitoring time. We further recommend the application and funding of behaviour change methods applied to fishers with the incorporation of conventional financial, conservation and regulatory tools to support resource management. Limitations Our results show that focussing on specific behaviours with appropriate measurement is both resource and time demanding to solve pressing conservation problems, particularly ones generated by complex industries such as fishing. Various lessons, useful for other social marketers, have been drawn from our evaluation of the overall study.


2020 ◽  
pp. SP511-2020-55
Author(s):  
P. J. Mudie ◽  
F. Marret ◽  
P. R. Gurdebeke ◽  
J. D. Hartman ◽  
P. C. Reid

AbstractNine non-pollen palynomorph (NPP) groups occur in Quaternary marine and brackish water sediments; these groups represent various planktonic or micro- to macrobenthic organisms. Some extant NPP were previously classified as fossil Acritarcha, Chitinozoa or scolecodonts. We refer to reviews of these fossils and their applications for Paleozoic-Mesozoic biostratigraphy and palaeoecology but focus on extant marine NPP that can be studied by laboratory culture, genetics or micro-geochemical methods. Marine NPP include resting cysts of planktonic dinoflagellates and prasinophytes, tintinnids and other cilates, copepod eggs and skeletal remains, and various microzoobenthos: microforaminiferal organic linings, ostracod mandibles and carapace linings, various worm egg capsules and mouthparts. New micro-Fourier Transform Infrared spectroscopy spectra suggest the probable affinities of the tintinnid cyst type P and Beringiella. Our applications in marine biodiversity and provincialism studies emphasize under-studied polar regions and neglected ice-algae nano-plankton, and compare climate-based NPP distributions to Ocean Biogeographic Information System realms. Trophic relationships are outlined using sediment-trap studies. Seasonal to annual-scale investigations of palaeoproduction provide new perspectives on ocean carbon budgets during times of rapid climate change and atmospheric carbon increase. More taxonomic and source-linkage studies of non-dinocyst marine NPP are needed but we outline potentials for studies of hemispheric or global-scale shifts in marine food webs as driven by ocean warming.


2014 ◽  
Vol 72 (3) ◽  
pp. 741-752 ◽  
Author(s):  
Miranda C. Jones ◽  
William W. L. Cheung

Abstract Species distribution models (SDMs) are important tools to explore the effects of future global changes in biodiversity. Previous studies show that variability is introduced into projected distributions through alternative datasets and modelling procedures. However, a multi-model approach to assess biogeographic shifts at the global scale is still rarely applied, particularly in the marine environment. Here, we apply three commonly used SDMs (AquaMaps, Maxent, and the Dynamic Bioclimate Envelope Model) to assess the global patterns of change in species richness, invasion, and extinction intensity in the world oceans. We make species-specific projections of distribution shift using each SDM, subsequently aggregating them to calculate indices of change across a set of 802 species of exploited marine fish and invertebrates. Results indicate an average poleward latitudinal shift across species and SDMs at a rate of 15.5 and 25.6 km decade−1 for a low and high emissions climate change scenario, respectively. Predicted distribution shifts resulted in hotspots of local invasion intensity in high latitude regions, while local extinctions were concentrated near the equator. Specifically, between 10°N and 10°S, we predicted that, on average, 6.5 species would become locally extinct per 0.5° latitude under the climate change emissions scenario Representative Concentration Pathway 8.5. Average invasions were predicted to be 2.0 species per 0.5° latitude in the Arctic Ocean and 1.5 species per 0.5° latitude in the Southern Ocean. These averaged global hotspots of invasion and local extinction intensity are robust to the different SDM used and coincide with high levels of agreement.


Paleobiology ◽  
1997 ◽  
Vol 23 (4) ◽  
pp. 410-419 ◽  
Author(s):  
Arnold I. Miller

Although available paleobiological data indicate that the geographic ranges of marine species are maintained throughout their entire observable durations, other evidence suggests, by contrast, that the ranges of higher taxa expand as they age, perhaps in association with increased species richness. Here, I utilize a database of Ordovician genus occurrences collected from the literature for several paleocontinents to demonstrate that a significant aging of the global biota during the Ordovician Radiation was accompanied by a geographic and environmental expansion of genus ranges. The proportion of genera occurring in two or more paleocontinents in the database, and two or more environmental zones within a six-zone onshore-offshore framework, increased significantly in the Caradocian and Ashgillian. Moreover, widespread genera tended to be significantly older than their endemic counterparts, suggesting a direct link between their ages and their environmental and geographic extents. Expansion in association with aging was corroborated further by demonstrating this pattern directly among genera that ranged from the Tremadocian through the Ashgillian. Taken together, these results are significant not only for what they reveal about the kinetics of a major, global-scale diversification, but also for what they suggest about the interpretation of relationships between diversity trends at the α (within-community) and β (between-community) levels.


2006 ◽  
Vol 63 (9) ◽  
pp. 2028-2037 ◽  
Author(s):  
Christophe Lejeusne ◽  
Thierry Pérez ◽  
Vanessa Sarrazin ◽  
Pierre Chevaldonné

Northwestern Mediterranean warming-related disease outbreaks and species shifts have recently been documented. Biomarkers of short-term effects on the health or resistance of organisms are necessary to assess and understand mechanisms affecting marine biodiversity. Heat-shock protein (HSP) expression was here believed to present finer variations than previously reported in experimental studies, which we tested to assess HSP sensitivity and relevance in the global warming context. One population of the "thermophilic" marine cave mysid Hemimysis margalefi was monitored over 4 years. Three HSPs presented recurrent expression. Among them, HSP50 and HSP60 expressions varied seasonally with environmental temperature. HSP60 expression displayed the greatest variability and was most closely related to temperature fluctuations. Multiple regression showed that while the main stressor was temperature, demographic variables (proportion of immatures, proportion of gravid females) also influenced expression variability. Such a monitoring of HSP baseline expression in a natural population had only rarely been conducted. HSPs are, however, good biomarkers to evaluate the effects of warming episodes or heat stress in the wild. This study provides essential spatial and temporal reference for further experimental and in situ analyses and is a prerequisite to diagnostic and predictive approaches.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Jakob Thyrring ◽  
Lloyd S Peck

Whether global latitudinal diversity gradients exist in rocky intertidal a-diversity and across functional groups remains unknown. Using literature data from 433 intertidal sites, we investigated α-diversity patterns across 155° of latitude, and whether local-scale or global-scale structuring processes control α-diversity. We, furthermore, investigated how the relative composition of functional groups changes with latitude. α-diversity differed among hemispheres with a mid-latitudinal peak in the north, and a non-significant unimodal pattern in the south, but there was no support for a tropical-to-polar decrease in α-diversity. Although global-scale drivers had no discernible effect, the local-scale drivers significantly affected α-diversity, and our results reveal that latitudinal diversity gradients are outweighed by local-processes. In contrast to α-diversity patterns, three functional groups: predators, grazers and suspension-feeders diversity declined with latitude, coinciding with an inverse gradient in algae. Polar and tropical intertidal data were sparse, and more sampling is required to improve knowledge of marine biodiversity.


Sign in / Sign up

Export Citation Format

Share Document