Diverse and changing use of the Salish Sea by Pacific salmon, trout, and char

Each year, juveniles of eight salmonid species enter the Salish Sea - the inland marine waters between northwestern Washington, USA and British Columbia, Canada. These species vary in the proportions remaining there and migrating to feed in the Pacific Ocean. Such differential migration affects their growth rates, and exposure to habitat alteration, predators, fisheries, and contaminants. We review these diverse migration patterns and present data from Puget Sound illustrating the variation in downstream migration timing, residency in the Salish Sea, and upriver return timing. Recreational catch records indicate that proportionally fewer remain in the Salish Sea than in past decades for several species, and the declines began after peaks in the late 1970s – early 1980s. These declines resist easy explanation because the factors controlling residency are poorly understood, and the Salish Sea has changed over the past decades. Regardless of the cause, the diversity of migration patterns is important to the ecology of the salmon and trout species, and to the humans and other members of the Salish Sea community with which they interact.

At a snail’s pace: the influence of habitat disturbance on terrestrial snail movement using experimentally manipulated mesocosms

The Anthropocene marks great changes to environments and the animals that inhabit them. Changes, such as disturbance, can affect the manner in which animals interact with their environments, such as moving and selecting habitats. To test how animals might respond to changing disturbance regimes, we employ an experimental approach to movement ecology. We used integrated step selection analysis (iSSA) to test the behavioural responses of individually-marked grove snails (Cepaea nemoralis) exposed to a gradient of physical disturbance in their habitat. We used a before-after control-impact (BACI) experimental design within semi-controlled mesocosms to manipulate edge and disturbance variables by altering the area of the mesocosm covered by bricks. We showed that grove snails perceive edges of enclosures and edges of bricks as risks, and responded to such risks by altering their movement. Grove snails displayed a bimodal response to risk by taking shelter in place or moving faster to be farther from the disturbance. Furthermore, individuals tended to modulate their behavioural response to the degree of risk. Our study highlights the usefulness of experimental mesocosms in movement ecology and in determining the effects of habitat alteration and human-imposed risk on movement behaviour.

Agricultural Fast Food: Bats Feeding in Banana Monocultures Are Heavier but Have Less Diverse Gut Microbiota

Habitat alteration for agriculture can negatively affect wildlife physiology and health by decreasing diet diversity and increasing exposure to agrochemicals for animals foraging in altered landscapes. Such negative effects may be mediated by the disruption of the gut microbiota (termed dysbiosis), yet evidence for associations between habitat alteration, wildlife health, and the gut microbiota remains scarce. We examine the association between management intensity of banana plantations and both the body condition and gut microbiota composition of nectar-feeding bats Glossophaga soricina, which commonly forage within banana plantations across Latin America. We captured and measured 196 bats across conventional monocultures, organic plantations, and natural forests in Costa Rica, and quantified gut microbiome bacterial phylogenetic diversity using 16S rRNA amplicon sequencing. We found that gut microbiota from bats foraging in conventional monocultures were overall less phylogenetically diverse than those from bats foraging in organic plantations or natural forests, both of which were characterized by diverse bacterial assemblages and individualized microbiota. Despite lower diversity, co-occurrence network complexity was higher in conventional monocultures, potentially indicating altered microbial interactions in agricultural landscapes. Bats from both organic and conventional plantations tended to be larger and heavier than their forest counterparts, reflecting the higher food supply. Overall, our study reveals that whilst both conventional monocultures and organic plantations provide a reliable food source for bats, conventional monocultures are associated with less diverse and potentially dysbiotic microbiota, whilst organic plantations promote diverse and individualized gut microbiota akin to their natural forest-foraging counterparts. Whilst the long-term negative effects of anthropogenically-altered microbiota are unclear, our study provides further evidence from a novel perspective that organic agricultural practices are beneficial for wildlife health.

On the diversity and abundance of riparian odonate fauna (Insecta) of the midstream Chalakkudy River, Kerala, India

The riparian Odonate insect diversity of the midstream Chalakudy River at six locations assessed from February 2018 to January 2019 has revealed the occurrence of 25 species of odonates. Among them,10 species are dragonflies belonging to seven genera of the family Libellulidae and the remaining 15 species are damselflies belonging to six families and 11 genera. Five endemic damselfly species have been recorded. Pseudagrion indicum is endemic to the Western Ghats, while the remaining four species, Vestalis apicalis, Libellago indica, Dysphaea ethela, and Heliocypha bisignata, are endemic to India. Diversity indices of the odonates in all the six locations were analyzed and it showed less abundance at sites where tourist activities are more and with thin native riparian vegetation. Further, the study has unequivocally revealed that thick native riparian vegetation is essential for their perching and existence. By and large, the uncontrolled tourism activities and habitat alteration interfere with the density and diversity of these endemic species.

Mangrove Health Assessment and Genetic Diversity of Associated Sesarmid Crab Parasesarma Persicum in Nayband National Park, Iran

Mangrove forests as one of the most important coastal ecosystems provide important ecological and economic performance to the world, have been threatened by developmental human activities and subsequent land use changes. The present study aims to assess mangrove ecosystem health in Nayband Marine National Park, Iran using Mangrove Quality Index (MQI), in addition to analyse the effect of mangrove habitat quality on the genetic diversity of Parasesarma persicum the associated mangrove crab by amplified fragment length polymorphism (AFLP). Four stations were studied for mangrove quality index analysis as well as genetic analysis. The results of MQI survey based on hydrology, water, soil, biota criteria indicated moderate to low habitat quality of mangroves in the study area. Station 4 in the southern Nayband gulf showed highest impact by human activities and MQI of 0.7, indicating serious habitat alteration in this area. Station 2 in the northern part of Nayband gulf showed a moderate mangrove quality (MQI = 0.5). Based on the results of the AFLP genetic assessment, the estimated heterozygosity(He) of crabs was between 0.29 to 0.32 with a mean of 0.30. The highest genetic diversity was found at station 2, however, no complete population differentiation was observed between 4 stations. The analysis revealed a significant correlation between mangrove habitat alteration and heterozygosity reduction (P<0.05). Based on the results of the present study, mangrove habitat destruction due to anthropogenic activities may directly reduce the genetic diversity of associated species of this ecosystem.

Philately’s Implications in Ecological Education via Romanian Thematic Joint Issues (IV)- Regarding the 2nd Collaboration with WWF

The project to promote the protected natural heritage and biodiversity continues with the 2nd collaboration of the Romanian postal administration with the World Wildlife Fund. Introducing in the scientific circulation the idea of thematic philately, for the protection of endangered species, this time we focused on the issue published in 1984. This is suggestively entitled “Animals protected in the Romanian reservations”. It should be mentioned that, at the end of 1984, the national thematic philately was enriched, with a series of postage stamps promoting pelicans. The philatelic issue comes to the public to confirm that in Romania (more exactly in Danube Delta Biosphere Reserve) there is the largest colony of common pelicans in Europe. The research emphasizes the mass character of thematic philately and its role as a cultural ambassador. The 1984 philatelic issue, underlines the implications of WWF, along with those of the Romanian postal administration, in promoting the natural capital to be protected. The issue itself has many philatelic effects (especially maximum postcards), both those made privately and officially, which we insisted. We wanted to show that such philatelic materials, made in collaboration with prestigious entities, are more than welcome in sounding the alarm about habitat alteration. Also, they can be the basis of various conservation strategies in terms of adequate information among tourists.

Trophic consequences of terrestrial eutrophication for a threatened ungulate

Changes in primary productivity have the potential to substantially alter food webs, with positive outcomes for some species and negative outcomes for others. Understanding the environmental context and species traits that give rise to these divergent outcomes is a major challenge to the generality of both theoretical and applied ecology. In aquatic systems, nutrient-mediated eutrophication has led to major declines in species diversity, motivating us to seek terrestrial analogues using a large-mammal system across 598 000 km 2 of the Canadian boreal forest. These forests are undergoing some of the most rapid rates of land-use change on Earth and are home to declining caribou ( Rangifer tarandus caribou ) populations. Using satellite-derived estimates of primary productivity, coupled with estimates of moose ( Alces alces ) and wolf ( Canis lupus ) abundance, we used path analyses to discriminate among hypotheses explaining how habitat alteration can affect caribou population growth. Hypotheses included food limitation, resource dominance by moose over caribou, and apparent competition with predators shared between moose and caribou. Results support apparent competition and yield estimates of wolf densities (1.8 individuals 1000 km −2 ) above which caribou populations decline. Our multi-trophic analysis provides insight into the cascading effects of habitat alteration from forest cutting that destabilize terrestrial predator–prey dynamics. Finally, the path analysis highlights why conservation actions directed at the proximate cause of caribou decline have been more successful in the near term than those directed further along the trophic chain.

Continued preference for suboptimal habitat reduces bat survival with white-nose syndrome

Habitat alteration can influence suitability, creating ecological traps where habitat preference and fitness are mismatched. Despite their importance, ecological traps are notoriously difficult to identify and their impact on host–pathogen dynamics remains largely unexplored. Here we assess individual bat survival and habitat preferences in the midwestern United States before, during, and after the invasion of the fungal pathogen that causes white-nose syndrome. Despite strong selection pressures, most hosts continued to select habitats where disease severity was highest and survival was lowest, causing continued population declines. However, some individuals used refugia where survival was higher. Over time, a higher proportion of the total population used refugia than before pathogen arrival. Our results demonstrate that host preferences for habitats with high disease-induced mortality can create ecological traps that threaten populations, even in the presence of accessible refugia.