Contamination by Persistent Chlorinated Endocrine Disrupters in Cetaceans from the North Pacific and Asian Coastal Waters

Abstracts of 3rd UNU-ORI joint international workshop for marine environment海洋環境国際ワークショップ講演要

High aboveground carbon stock of African tropical montane forests

Tropical forests store 40-50 per cent of terrestrial vegetation carbon(1). However, spatial variations in aboveground live tree biomass carbon (AGC) stocks remain poorly understood, in particular in tropical montane forests(2). Owing to climatic and soil changes with increasing elevation(3), AGC stocks are lower in tropical montane forests compared with lowland forests(2). Here we assemble and analyse a dataset of structurally intact old-growth forests (AfriMont) spanning 44 montane sites in 12 African countries. We find that montane sites in the AfriMont plot network have a mean AGC stock of 149.4 megagrams of carbon per hectare (95% confidence interval 137.1-164.2), which is comparable to lowland forests in the African Tropical Rainforest Observation Network(4) and about 70 per cent and 32 per cent higher than averages from plot networks in montane(2,5,6) and lowland(7) forests in the Neotropics, respectively. Notably, our results are two-thirds higher than the Intergovernmental Panel on Climate Change default values for these forests in Africa(8). We find that the low stem density and high abundance of large trees of African lowland forests(4) is mirrored in the montane forests sampled. This carbon store is endangered: we estimate that 0.8 million hectares of old-growth African montane forest have been lost since 2000. We provide country-specific montane forest AGC stock estimates modelled from our plot network to help to guide forest conservation and reforestation interventions. Our findings highlight the need for conserving these biodiverse(9,10) and carbon-rich ecosystems. The aboveground carbon stock of a montane African forest network is comparable to that of a lowland African forest network and two-thirds higher than default values for these montane forests.Peer reviewe

Geographic variation in skull morphology of humpback dolphins (<i>Sousa</i> spp.)

The taxonomy and systematic relationships of humpback dolphins (genus Sousa) are highly confused. This is largely due to a lack of data and samples from large portions of the range of the genus, and confusing and seemingly contradictory patterns of variation in available external morphometric, skeletal morphometric, and molecular datasets. To help clarify the situation, we measured 222 skulls of humpback dolphins originating from throughout most regions of the range of Sousa. While patterns of cranial variation appeared to be relatively conservative, there was evidence for three groups: (1) Atlantic Ocean/West Africa, (2) Western Indian Ocean, and (3) Eastern Indian Ocean/Pacific Ocean. These would appear to correspond to the teuszii, plumbea, and chinensis forms, respectively. No taxonomic revisions are recommended at this time, and the conservative view of two species (S. teuszii in West Africa and S. chinensis in the Indo-Pacific) can be defended for the time being as a pragmatic approach. The distinctness of S. teuszii is clearcut, but other taxonomic decisions should await further studies of molecular genetics and morphometrics, currently underway

The taxonomic status of the nominal dolphin species <i>Delphinus tropicalis</i> Van Bree, 1971

The taxonomic status of common dolphins in the Atlantic and Pacific oceans has been clarified in recent years, with the discovery that there appear to be two species, a short-beaked (Delphinus delphis) and a long-beaked (D. capensis) species. However, the taxonomy of common dolphins in the Indian Ocean and southeast Asia is still unclear. A nominal third species, Delphinus tropicalis van Bree, 1971, has been described from this area, but its validity is controversial. We reviewed records and literature on common dolphins from South Africa east to Australia and Japan, and measured 206 skulls of common dolphins from the Indo-Pacific and southern California. Other than southern Australia, we found no evidence for Delphinus delphis in the Indo-Pacific (South African specimens appear to be D. capensis). Previous reports of short-beaked common dolphins in the Indo-Pacific appear to have been cases of misidentification. The tropicalis-form has an exceptionally long and narrow rostrum with high tooth counts, but otherwise appears to resemble D. capensis, in both skeletal and external morphology. From an examination of 86 Delphinus skulls from the reported range of tropicalis (Middle East to China), we found that both tooth counts and rostral length/zygomatic width ratios were higher than for 94 D. capensis specimens from southern Japan, South Africa, and California. These measurements were greatest in the central Indian Ocean (around India). However, there was evidence of clinal variation, with both decreasing as one moves east or west from India, towards South Africa in the west or Japan in the east. We suggest that the tropicalis-form is actually a long-beaked subspecies of D. capensis, which may hybridize or intergrade with the standard capensis-form in southeast Asia and possibly along the east coast of Africa. The appropriate name is Delphinus capensis tropicalis (van Bree, 1971), and a formal description of the subspecies is provided