Persistent organochlorine residues in small cetaceans from the east and west coasts of southern Africa

Kock, Anrich; Best, Peter B.; Cockcroft, Victor G.; Bosma, C.

doi:10.1016/0048-9697(94)90085-x

Cited by 53 publications

(20 citation statements)

References 21 publications

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“…Long-term or year-round studies are unavailable for the other cetacean species known to occur along this section of the South African coast and it is unknown how they are affected by human impacts. There are multiple anthropogenic threats to marine life along the southern African coast including physical changes to the coastline (Sink et al, 2012), pollution (Atkinson & Sink, 2008;Cockcroft, de Kock, Lord, & Ross, 1989;de Kock, Best, Cockcroft, & Bosma, 1994), potential establishment of nuclear power stations (Griffiths & Robinson, 2011), effects of fisheries including depletion of prey (Atkinson & Sink, 2008), entanglement in fishing gear (Atkinson & Sink, 2008;Meÿer et al, 2011), boat traffic including recreational, ecotourism, and fishing vessels (Elwen & Leeney, 2010;Meÿer et al, 2011;Turpie, Savy, Clark, & Atkinson, 2005;Waerebeek et al, 2006), and tourism in a broader sense (Sink et al, 2012). However, whereas knowledge of the abundance of animals, their distribution, genetic variability, and behavior is a basic requirement for effective conservation of species and ecosystems (Caughley & Sinclair, 1994), acquiring such data for cetaceans is difficult and costly (Redfern et al, 2006).…”

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confidence: 98%

The Use of Data from a Platform of Opportunity (Whale Watching) to Study Coastal Cetaceans On the Southwest Coast of South Africa

Vinding¹,

Bester²,

Kirkman³

et al. 2015

Tourism in Marine Environments

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Effective conservation management requires information on wildlife abundance and distribution. Platforms of opportunity, including whale-watching vessels (WWV), can provide inexpensive and valuable information particularly in data deficient areas. This study analyzed over 5,500 cetacean encounters from more than 2,500 trips over 10 years by a WWV in the Western Cape, South Africa. Results were twofold: 1) providing spatial and temporal distribution patterns of the five main cetacean species for the area (southern right, humpback, and Bryde's whales, Indo-Pacific bottlenose and Indian Ocean humpback dolphins) and the first long-term, year-round data for this area; 2) showing that regularly recorded opportunistic encounters from a WWV constitute an important source of baseline information. Caveats and limitations of data from WWV are discussed and advice regarding data collection from platforms of opportunity is provided. Particularly, the lack of effort data and of clearly defined behavioral categories is emphasized and standardization of guidelines for data collection methods worldwide is suggested.

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mentioning

confidence: 98%

The Use of Data from a Platform of Opportunity (Whale Watching) to Study Coastal Cetaceans On the Southwest Coast of South Africa

Vinding¹,

Bester²,

Kirkman³

et al. 2015

Tourism in Marine Environments

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“…Concentration values of total PCBs found in the blubber of cetaceans from different parts of the Mediterranean, such as the Ligurian and North Tyrrhenian Seas [8], the coast of Catalonia [22], and the French coast [23], are similar to our values (according to our previously reported data in striped dolphins from the Mediterranean Sea [16], the total PCB concentration found in blubber was approx four times higher than that found in liver tissue). They are consistently higher than those found in the open sea, such as dolphins from the western Pacific [24], the south Atlantic [25], the east Pacific [26] and the United States (Atlantic) [27], for which values ranged from 6 to 59 μg/g (fat weight) in blubber tissues.…”

Section: Resultsmentioning

confidence: 99%

Isomer‐specific polychlorinated biphenyl determination in cetaceans from the mediterranean sea: Enantioselective occurrence of chiral polychlorinated biphenyl congeners

Jiménez

Jiménez²,

González³

2000

Enviro Toxic and Chemistry

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Isomer-specific concentrations of 41 polychlorinated biphenyls (PCBs) and the enantiomeric ratios (ER) of nine chiral PCBs were determined in the liver of four cetacean species-Risso's dolphin (Grampus griseus), bottlenose dolphin (Tursiops truncatus), fin whale (Balaenoptera physalus), and long-finned pilot whale (Globicephala melaena)-found dead in the Mediterranean Sea. The total PCB concentration (sum of 41 congeners) ranged from 484 to 63,200 ng/g wet weight. The 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) toxic equivalents (TEQs), as defined by the World Health Organization (WHO), ranged from 4.3 to 1,454 pg/g wet weight. The contribution of mono-ortho PCBs was consistently higher than non-ortho PCB congeners, in whale species, whereas in dolphins this predominance was not so clear. The PCB profiles were dominated by congeners 138, 153, and 180 in almost all the investigated samples. Comparison of PCB profiles by using principal component analysis allowed to separate the species into different groups. Polychlorinated biphenyls 170 and 180 seem to be eliminated by the two whale species, and PCB 180 also seems to be eliminated by Risso's dolphins. The PCBs 95, 132, 149, and 176 revealed an enantiomeric excess of the second eluted enantiomer in almost all the cetaceans investigated, where 136 and 174 were racemic or almost racemic. It is the first time that an enantiomeric excess of PCB 84 and 91 has been reported in biological samples. Although it was only possible to calculate them in two dolphin liver samples, the high values of enantiomeric excess found are surprising (86.3 and 32% for PCB 91 and 84, respectively).

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“…Furthermore, the long life span of humpback dolphins and their position at the top of the coastal food chain contributes to pollutant accumulation. The residue levels of chlorinated hydrocarbons (PCBs, DDT and dieldrin) in humpback dolphins from the KwaZulu-Natal coast were reported to be higher than in any other marine mammal from the region (Cockcroft, 1989;Cockcroft et al, 1991;De Kock et al, 1994). These pollutants are known to be strongly immunosuppressive (Vos & De Roy, 1972), possibly carcinogenic (Martineau et al, 1994) and cause severe reproductive abnormalities (Reijnders, 1980;Subramanian et al, 1987).…”

Section: Implications For the Conservation Of Humpback Dolphinsmentioning

confidence: 99%

Conservation and management of humpback dolphins: the South African perspective*

Karczmarski¹

2000

ORX

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Population biology and socio-ecology of Indo-Pacific humpback dolphins Sousa chinensis were investigated during a 3-year study period in the Algoa Bay region, South Africa. The dolphins inhabit a narrow strip of coastal waters, mostly less than 15 m deep. Groups are small (mean = 7 animals) and their daily activities concentrate around shallow rocky reefs-the primary feeding grounds. Dependence on these restricted, shallow-water habitats is evident throughout the year. Site fidelity is generally weak and is subject to seasonal migration, although female site fidelity seems to be related to reproductive stage. Births occur predominantly in summer. The social system is highly fluid, structured to some degree by sex and age, 'matesearching' behaviour being the most likely male reproductive strategy. The dolphins inhabiting Algoa Bay are part of a substantially larger population that uses a considerable length of the coastal zone. Estimated population parameters are generally low, as are modelled population growth rates, and an increase in the population size seems unlikely. Humpback dolphins appear to be vulnerable to negative environmental pressure and the alteration/destruction of inshore habitats is probably among the greatest threats to them. Conservation of this species should be given high priority and be seen as an important part of integrated coastal zone management. Establishment of multiple-use management areas with controlled ecotourism and several priority sites declared as strict reserves seems to be the most effective conservation approach. In order to be successful, conservation and management policies need to recognize the needs and lifestyles of the local inhabitants.

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Persistent organochlorine residues in small cetaceans from the east and west coasts of southern Africa

Cited by 53 publications

References 21 publications

The Use of Data from a Platform of Opportunity (Whale Watching) to Study Coastal Cetaceans On the Southwest Coast of South Africa

The Use of Data from a Platform of Opportunity (Whale Watching) to Study Coastal Cetaceans On the Southwest Coast of South Africa

Isomer‐specific polychlorinated biphenyl determination in cetaceans from the mediterranean sea: Enantioselective occurrence of chiral polychlorinated biphenyl congeners

Conservation and management of humpback dolphins: the South African perspective*

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