3 research outputs found
Helminth parasites of Caspian kilka (genus Clupeonella) as bioindicators of heavy metals
In the present study, intestinal helminth parasite fauna of 398 specimens of three
species of kilkas, C. engrauliformis (N= 92), C. grimmi (N= 136) and
C. cultriventris (N= 170) from Babolsar harbor were investigated. Five parasite
species were found including: Corynosoma strumosum (Acanthocephala),
Pronoprymna ventricosa (Trematoda), Contracaecum sp. (Nematoda),
Raphidascaris sp. (Nematoda) and Anisakis sp. (Nematoda). The highest
prevalence and abundance were observed in C. strumosum and P. ventricosa.
The prevalence and abundance of C. strumosum in C. grimmi was significantly
higher than C. engrauliformis. The prevalence and abundance of P. ventricosa in
C. cultriventris was significantly higher than C. engrauliformis. The prevalence,
mean intensity and mean abundance of the parasites were compared according
to the sex, length group and season also effect of parasite on host growth
parameters was considered. The diversity, equability, similarity, species
richness, dominance Indices and specificity indices of helminth parasites of the
three host species were studied.
Also the lead and cadmium concentrations in the intestine, muscle, liver, kidney
and gonad of kilkas and their parasites C. strumosum and P. ventricosa were
measured and compared. The results revealed that lead and cadmium
concentrations in C. strumosum and P. ventricosa were significantly higher
than kidney, liver, intestine, gonad and muscle. The lead and cadmium
concentrations of the parasites were compared according to the sex, parasitism
and season
Colony site characteristics of sympatric breeding tern species on the Mond Islands, the Persian Gulf
We have investigated characteristics of colony site of three sympatric breeding tern species on small islands of a subtropical region, the Persian Gulf. The three most populous ground-nesting waterbird species – Bridled Tern Onychoprion anaethetus, Lesser Thalasseus bengalensis and Greater Thalasseus bergii Crested Terns – were studied during the 2009–2011 breeding seasons. The average area size of mixed colonies was 454 m2. The density of nests of the Bridled Tern was 846 nests/ha. The proportion of the number of nests in a mixed colony for Lesser Crested Tern (5546 nests) was approximately 10-fold compared to the Greater Crested Tern (542 nests). The density of Bridled Tern nests/ha was significantly higher in areas with 50–75% vegetation cover (>1200 nests/ha) than in areas of <5% vegetation cover (72–105 nests/ha) (p < 0.05). Mixed colonies of the Lesser and Greater Crested Terns were located on unvegetated land, at an average distance of 4.1 m to vegetation, and on sandy soil (79.4% on average) and above high spring tide water lines (0.59 m on average). There were more potential nesting areas than occupied areas for the mixed colonies of the Lesser and Greater Crested Terns, indicated that they did not face nest site limitation
What's on the horizon for community-based conservation? Emerging threats and opportunities
Community-based conservation can support livelihoods and biodiversity, while reinforcing local and Indigenous values, cultures, and institutions. Its delivery can help address cross-cutting global challenges, such as climate change, conservation, poverty, and food security. Therefore, understanding trends in community-based conservation is pertinent to setting and implementing global goals. We undertook a horizon scan to prioritize 15 emerging threats and opportunities expected to impact the future effectiveness of community-based conservation. Topics relate to global biodiversity policy; human rights; shifting human geography; inclusion, diversity, equity, and access; conservation finance and income; and economic reforms. Our findings offer guidance on strengthening community-based conservation to achieve global environmental and development goals