scholarly journals Overfishing and habitat loss drive range contraction of iconic marine fishes to near extinction

2021 ◽  
Vol 7 (7) ◽  
pp. eabb6026
Author(s):  
Helen F. Yan ◽  
Peter M. Kyne ◽  
Rima W. Jabado ◽  
Ruth H. Leeney ◽  
Lindsay N.K. Davidson ◽  
...  
Keyword(s):  
Habitat Loss ◽  
Coastal Waters ◽  
Marine Fishes ◽  
Similar Species ◽  
Range Contraction ◽  
Historical Distribution ◽  
Local Extinctions ◽  
Near Extinction ◽  
Over Time

Extinctions on land are often inferred from sparse sightings over time, but this technique is ill-suited for wide-ranging species. We develop a space-for-time approach to track the spatial contraction and drivers of decline of sawfishes. These iconic and endangered shark-like rays were once found in warm, coastal waters of 90 nations and are now presumed extinct in more than half (n = 46). Using dynamic geography theory, we predict that sawfishes are gone from at least nine additional nations. Overfishing and habitat loss have reduced spatial occupancy, leading to local extinctions in 55 of the 90 nations, which equates to 58.7% of their historical distribution. Retention bans and habitat protections are urgently necessary to secure a future for sawfishes and similar species.

scholarly journals A survey of fish viruses isolated from wild marine fishes from the coastal waters of southern Korea

2013 ◽  
Vol 25 (6) ◽  
pp. 750-755 ◽  
Author(s):  
Wi-Sik Kim ◽  
Shin-Young Choi ◽  
Do-Hyung Kim ◽  
Myung-Joo Oh
Keyword(s):  
Coastal Waters ◽  
Marine Fishes ◽  
Southern Korea ◽  
Fish Viruses

The Ecology of Juvenile Salmon in the Northeast Pacific Ocean: Regional Comparisons

2007 ◽  
Keyword(s):  
Coastal Waters ◽  
Pacific Salmon ◽  
Size Class ◽  
Small Fish ◽  
Lepeophtheirus Salmonis ◽  
Northeast Pacific ◽  
Salmon Lice ◽  
Regional Comparisons ◽  
Northeast Pacific Ocean ◽  
Over Time

Abstract.—We report patterns of infestation with motile salmon lice, <em>Lepeophtheirus salmonis</em>, on Pacific salmon collected with a surface trawl in coastal waters of Oregon, Washington, British Columbia, and Alaska during 2002 and 2003. Salmon lice were observed on all salmon species examined and in all areas surveyed. The prevalence and abundance of lice infestation varied significantly among species, size-classes, seasons, regions, and years, with larger salmon being consistently more heavily infested than small salmon. The number of lice infesting the small size-class (100–400 mm) of salmon rarely exceeded 5 lice per fish with a mean abundance generally below 0.2 lice per fish. Lice prevalence and, to a lesser extent, lice abundance increased over time in small fish, with lower values during spring and higher values in the following winter, and continued to increase in larger and older fish. There were no apparent effects of water temperature on lice infestation in Pacific salmon. This study suggested that salmon infested with lice remained in coastal waters throughout the year. We suggest that lice on salmon that overwinter in coastal waters will contribute to a pool of infective copepodids in these habitats.

scholarly journals Grassland-to-crop conversion in agricultural landscapes has lasting impact on the trait diversity of bees

2020 ◽  
Author(s):  
Gaëtane Le Provost ◽  
Isabelle Badenhausser ◽  
Cyrille Violle ◽  
Fabrice Requier ◽  
Marie D’Ottavio ◽  
...  
Keyword(s):  
Land Use ◽  
Habitat Loss ◽  
Agricultural Landscapes ◽  
Habitat Destruction ◽  
Land Use History ◽  
Pollinator Decline ◽  
Plant Trait ◽  
Trait Diversity ◽  
Bee Communities ◽  
Over Time

Abstract Context Global pollinator decline has motivated much research to understand the underlying mechanisms. Among the multiple pressures threatening pollinators, habitat loss has been suggested as a key-contributing factor. While habitat destruction is often associated with immediate negative impacts, pollinators can also exhibit delayed responses over time. Objectives We used a trait-based approach to investigate how past and current land use at both local and landscape levels impact plant and wild bee communities in grasslands through a functional lens. Methods We measured flower and bee morphological traits that mediate plant–bee trophic linkage in 66 grasslands. Using an extensive database of 20 years of land-use records, we tested the legacy effects of the landscape-level conversion of grassland to crop on flower and bee trait diversity. Results Land-use history was a strong driver of flower and bee trait diversity in grasslands. Particularly, bee trait diversity was lower in landscapes where much of the land was converted from grassland to crop long ago. Bee trait diversity was also strongly driven by plant trait diversity computed with flower traits. However, this relationship was not observed in landscapes with a long history of grassland-to-crop conversion. The effects of land-use history on bee communities were as strong as those of current land use, such as grassland or mass-flowering crop cover in the landscape. Conclusions Habitat loss that occurred long ago in agricultural landscapes alters the relationship between plants and bees over time. The retention of permanent grassland sanctuaries within intensive agricultural landscapes can offset bee decline.

scholarly journals Recent responses to climate change reveal the drivers of species extinction and survival

2020 ◽  
Vol 117 (8) ◽  
pp. 4211-4217 ◽  
Author(s):  
Cristian Román-Palacios ◽  
John J. Wiens
Keyword(s):  
Climate Change ◽  
Animal Species ◽  
Biodiversity Loss ◽  
Climatic Changes ◽  
Important Work ◽  
Species Extinction ◽  
Major Threat ◽  
Niche Shifts ◽  
Local Extinctions ◽  
Over Time

Climate change may be a major threat to biodiversity in the next 100 years. Although there has been important work on mechanisms of decline in some species, it generally remains unclear which changes in climate actually cause extinctions, and how many species will likely be lost. Here, we identify the specific changes in climate that are associated with the widespread local extinctions that have already occurred. We then use this information to predict the extent of future biodiversity loss and to identify which processes may forestall extinction. We used data from surveys of 538 plant and animal species over time, 44% of which have already had local extinctions at one or more sites. We found that locations with local extinctions had larger and faster changes in hottest yearly temperatures than those without. Surprisingly, sites with local extinctions had significantly smaller changes in mean annual temperatures, despite the widespread use of mean annual temperatures as proxies for overall climate change. Based on their past rates of dispersal, we estimate that 57–70% of these 538 species will not disperse quickly enough to avoid extinction. However, we show that niche shifts appear to be far more important for avoiding extinction than dispersal, although most studies focus only on dispersal. Specifically, considering both dispersal and niche shifts, we project that only 16–30% of these 538 species may go extinct by 2070. Overall, our results help identify the specific climatic changes that cause extinction and the processes that may help species to survive.

On two little-known microsporidia of marine fishes

Parasitology ◽  
1959 ◽  
Vol 49 (3-4) ◽  
pp. 309-315 ◽  
Author(s):  
Z. Kabata
Keyword(s):  
Coastal Waters ◽  
Parasite Fauna ◽  
Marine Fishes ◽  
Research Worker ◽  
Parasitic Species

Parasites of marine fishes have attracted, comparatively speaking, but little attention among scientists. This is true especially for the parasites of those fishes which live in the open seas, and are therefore less accessible to investigation than their relatives inhabiting coastal waters. On many occasions, when chance has brought such a parasite to the attention of a research worker, the scarcity of data allowed no more than mere recording of the existence and a brief description of the parasitic species. Now, when investigations into the parasite fauna of marine fishes are being intensified, it is possible to add to our knowledge of such forgotten species of parasites, in order to appreciate more clearly their possible importance to their hosts and, indirectly, to the economics of the stocks of our food fishes.

Distribution and abundance of Vancouver Island marmots (Marmota vancouverensis)

1996 ◽  
Vol 74 (4) ◽  
pp. 667-677 ◽  
Author(s):  
Andrew A. Bryant ◽  
Doug W. Janz
Keyword(s):  
Life Style ◽  
Vancouver Island ◽  
Population Fluctuations ◽  
Population Status ◽  
Patchy Distribution ◽  
Subalpine Meadows ◽  
South Central ◽  
Historic Records ◽  
Local Extinctions ◽  
Over Time

We analysed historic records and annual counts to assess the population status of Vancouver Island marmots (Marmota vancouverensis). Since 1972, marmots have been found at 47 sites on 15 mountains. All but 2 colonies were located within 5 adjacent watersheds on south-central Vancouver Island. Counts underestimated actual marmot abundance. For most site–year combinations, observers probably counted 66–78% of adults and 75–89% of juveniles. Reproductive colonies typically contained fewer than 5 adults ([Formula: see text], SE = 0.61, n = 34). Most animals were found at elevations above 1000 m (81%), on south- to west-facing slopes (74%). After 1981, marmots colonized 11 habitats created by logging of forests above 700 m. Numbers of adults were above average (134–147%) during the early 1980s and have been near or below average since 1990 (58–99%). The current (1995) population contains 100–200 animals, including 50–100 animals in logged habitats. Marmota vancouverensis is rare primarily because of the small size and patchy distribution of natural subalpine meadows on Vancouver Island. The species is apparently adapted to a metapopulation life-style, in which a network of small colonies exhibit population fluctuations, local extinctions and recolonizations over time.

scholarly journals Fungal Diversity in Multiple Post-harvest Aged Red Pine Stumps and Their Potential Influence on Heterobasidion Root Rot in Managed Stands Across Minnesota

2021 ◽  
Vol 2 ◽  
Author(s):  
Eric C. Otto ◽  
Benjamin W. Held ◽  
Trevor J. Gould ◽  
Robert A. Blanchette
Keyword(s):  
Biological Control Agent ◽  
Illumina Miseq ◽  
Diversity Indices ◽  
Control Agent ◽  
Red Pine ◽  
Similar Species ◽  
Native Range ◽  
Change Over Time ◽  
Phlebiopsis Gigantea ◽  
Over Time

Thinning operations that occur in managed red pine (Pinus resinosa) stands, create tree stumps that can serve as a habitat for fungi, especially Heterobasidion irregulare, the cause of a serious root disease. Different fungi can colonize stumps early and the community of fungi can change over time as initial fungal species become replaced. Samples were collected from both the native and non-native range of red pine from stumps that were cut at different time periods. Stumps that were harvested at 0–1, 2–3, 5–6, and 10–12 years before sampling were used to provide data on the diversity of fungi that colonize tree stumps and how these communities can change over time as well as how they influence colonization of H. irregulare. Traditional culturing methods and Illumina MiSeq sequencing were used to identify the fungi in the samples. Of particular interest was Phlebiopsis gigantea, which can colonize cut stumps and prevent H. irregulare from becoming established. Overall, P. gigantea was the most abundant fungus isolated and sequenced via Illumina MiSeq. Results show that Phlebiopsis gigantea was isolated from 90% of all stumps sampled for sites harvested within 3 years of sampling in the native range of red pine compared to 33% in the non-native range. For Illumina MiSeq, 5,940 total amplicon sequence variants (ASVs) were detected. P. gigantea represented 14% of the total reads and composed 19% of the reads in the native range and 8% in non-native range of red pine. Furthermore, P. gigantea represented 38% of the reads for stumps that were harvested within 3 years of sampling in the native range of red pine compared to 14% in the non-native range. These results help demonstrate that a higher amount of P. gigantea is present in the native range of red pine and could be acting as a native biological control agent. Additional fungi, including Resinicium bicolor, Hypochnicium cremicolor, Leptographium spp., and others identified at different cutting times are also discussed. Finally, different diversity indices revealed similar, but slightly higher diversity for southern sites via Shannon and Simpson Diversity indices. Beta diversity demonstrated a similar species composition in stumps harvested at different times with these stumps being grouped together based on harvesting years.

scholarly journals A qualitative and quantitative comparison of mite fauna between bifenthrin-treated and non-pesticide treated alfalfa hay fields in Central Greece

2020 ◽  
Vol 13 (1) ◽  
pp. 29-41
Author(s):  
E.G. Badieritakis ◽  
A.A. Fantinou ◽  
N.G. Emmanouel
Keyword(s):  
Spatial Distribution ◽  
Species Richness ◽  
New Record ◽  
Seasonal Fluctuation ◽  
Quantitative Comparison ◽  
Similar Species ◽  
Qualitative And Quantitative ◽  
Central Greece ◽  
Alfalfa Hay ◽  
Over Time

SummaryThe mite fauna in foliage and litter of a sprayed alfalfa hay field with the acaricide-insecticide bifenthrin, was studied based on monthly samplings from foliage and litter in Central Greece between 2008–2009. Potential differentiations between this field and two adjacent alfalfa hay fields, which were not subjected to pesticide applications and were managed with different number of cuttings, were also evaluated in terms of population fluctuation over time, population density, species richness, diversity and spatial distribution. The sprayed field hosted 50 and 68 species and morphospecies in foliage and litter respectively, depicting high relative abundance of oribatid and prostigmatic mites. Neoseiulus aristotelisi Papadoulis, Emmanouel and Kapaxidi, was a new record for alfalfa, previously found in rice in Macedonia, Greece. The seasonal fluctuation of mites, particularly in foliage, was similar in all fields. The spatial distribution of a Zygoribatula species, which was common and dominant in all fields, was also aggregated. Finally, the sprayed field shared similar mite diversity with the two non-sprayed fields, but not similar species richness.

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