Endangered coelacanths?

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We are constantly reminded that "coelacanths are an endangered" species. Anybody care to tell us what they are endangered from? Every known coelacanth capture has been accidental and they cannot be 'targetted' so there is NO danger from artisanal fishermen. Global (and therefore, sea) warming? - maybe just a little but this affects ALL marine and aquatic creatures. Marine pollution? - hardly though there is probably more runoff from adjacent land today than there was a century or more ago. So how come the coelacanth is supposed to be 'endangered'?

-- Robin Stobbs (r.stobbs@ru.ac.za), May 22, 2004

Answers

The latest IUCN Red list conservation assessment of THE coelacanth, Latimeria chalumnae, is available at http://www.iucnredlist.org/search/details.php?species=11375

The assessment, authored by J.A. Musick, classifies the coelacanth as Critically Endangered (CR A2cd, C2b - criteria 2.3 1994).

Given current knowledge this assessment is inadequate and needs to be updated. Perhaps this is an important and rewarding task for the Coelacanth Ecosystem Programme to take on.

The assessment category means that: (A2) a population reduction of at least 80% is projected, or suspected to be met within the next three generations, based on - (c)a decline in distribution, area occupied or habitat quality, and - (d)actual or potential levels of exploitation and, (C2b) The total species population is estimated to number fewer than 250 mature individuals AND an observed, predicted or inferred ongoing decline in the number of mature individuals AND all individuals are within a single subpopulation.

The details justifying this assessment are sparse. The only cited threat is ongoing accidental bycatch mortality.

* The country names given are Indonesia, Comoros and South Africa

* The range is given as Indo-West Pacific in the vicinity of Grand Comoro and Anjouan islands, the coast of South Africa, Mozambique and Madagascar.

* The major habitat types are listed as Shallow sea and Coastline - Karst and other subterranian hydrological systems.

*** Deficiencies, inaccuracies and contradictions The assessment could be contested in that documentation of the threats is inadeqate to justify the assigned status. The assessment also fails to consider several potential threatening processes. - There are no references to impact of accidental by-catch mortality on coelacanth populations (this requires some quantitative justification - even an estimate).

- There is no documentation and no suggested threatening process for the inferred decline in range or habitat quality

- There is no mention of the direct threat posed by fishing for coelacanth specimens. Given that the Comoros is politically unstable (19 coups in 29 years, several sponsored by outside adventurers) this could potentially become a serious threat.

- The criterion C2b is incorrectly applied as there are more than one single known population (the genetic difference between the Indonesian and Comoros populations suggests that these are separate populations, and it is likely that the South African population is also a separate demographic unit)

- There is no mention of the recently described, Latimeria menadoensis, and there is no separate Red list assessment for this species. The inclusion of Indonesia in the country list suggests that this taxon is subsumed in Latimeria chalumnae for this assessment. Laterimeria menadoensis has dubious taxonomic value. The only evidence supporting the recognition of this species is a moderate divergence in mitochondrial DNA sequences (see Holder et al 1999 PNAS 12616-12620 for an excellent summary). Mitochondrial DNA is generally considered unsuitable as the sole basis for species description, and the divergence between these populations is less than that observed between many historically isolated populations within other species - so special pleading is required to accept this taxon. Nonetheless the Red list entry should include some statement justifying the taxonomic separation or relegation of this species in the assessment.

- Although Indonesia is included in the country list, the given range does not include Menado Tua (near Sulawesi) where this population was discovered (Hans Fricke had difficulty finding coelacanths here, but did observe a couple off southern Sulawesi) nor does it include any other Indonesia locality. The range should also distinguish between sites where occasional coelacanths have been found, and those where they appear to be resident.

- Coelacanths have also been found off the coast of Mozambique, Tanzania, (Kenya?) and Madagascar.

- The habitat should be updated to include the different circumstances of the Sodwana Bay and Sulawesi sites which Hans Fricke suggested are both dissimilar to the Comoros (especially in terms of currents and geology). I'm not sure that the major habitat categories on offer are adequate for the coelacanth, and many other moderate depth coastal marine species. Should these really be lumped with species occurring in 'subterranian' coastal karst systems? Surely there should be a category for moderate depth rocky coastal systems with caves.

These problems suggest to me that the coelacanth RDB entry is more than a straight-forward conservation assessment and has been weighted by its scientific value.

-- Michael Cunningham (cunninghammj@qwa.uovs.ac.za), November 18, 2004.


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