Wide range of vulnerability seen for Philippine species

MALAYA BUSINESS INSIGHT

LOLONG is a critically endangered crocodile.

This, according to the latest updated Red List of Threatened Species released this month by the International Union for Conservation of Nature (IUCN).

The Red List, with more than 61,900 species reviewed, is an extensive collection of information on the threats to species, their ecological requirements, where they live and information on conservation actions that can be used to reduce or prevent extinctions.

Lolong is among the Philippine wildlife listed in the latest update of the Red List. Among them are the Philippine tarsier (Tarsius syrichta), classified as “Near Threatened”; Philippine Spurdog (Squalus montalbani), ” Vulnerable”; and the Philippine Butterflyfish (Chaetodon adiergastos), “Least Concern “.

They represent a wide range of species vulnerability, starting with the Philippines Crocodile (Crocodylus mindorensis) which is listed as “Critically Endangered”.

Critically Endangered, Endangered and Vulnerable species are considered threatened with global extinction. The classification is second only to Extinct or Extinct in the Wild in a descending order of threat.

It is followed by Near Threatened species which are close to the threatened thresholds or that would be threatened without ongoing specific conservation measures; and Least Concern species evaluated with a lower risk of extinction.

The terrestrial, freshwater Philippine Crocodile is found only in this country. While it is considered critically endangered, there is hope it is nowhere close to extinction as shown in the recent capture in the Agusan Marsh of Lolong, reputably the world’s largest (more than 1 ton) and longest (over 21 feet) crocodile.

Only about 250 Philippine crocodiles are believed to be in the wild. Conservation efforts include the release of juveniles in Isabela; they are raised in captivity in Palawan while reintroduction sites are planned in Mindoro and Negros. Unconfirmed sightings have been reported in some provinces.

Tarsier

The Philippine Tarsier has a relatively limited geographical range, from sea level up to 750 meters. It is found only in Bohol, Samar, Leyte, Davao del Norte, Davao del Sur, Misamis Occidental, Misamis Oriental, South Cotabato, and Zamboanga del Norte and Zamboanga del Sur. It has also been sighted in Basilan, Biliran, Maripipi and Bukidnon.

It is listed as Near Threatened, based on an estimated significant decline over the last 20 years because of habitat loss. It is hunted as food and for the pet trade.

In fact, because of decreasing population trend, it almost qualifies as threatened. While it is locally common and widespread, largely because of its tolerance of second growth habitat, it thrives best in less disturbed habitats such as primary forests, very little of which remains within its range.

It is susceptible to extinction because infant mortality rates, both in the wild and in captivity, are very high. It requires a highly specialized diet: small lizards, frogs and insects.

The IUCN says anecdotal reports indicate “the pet markets in Manila are being flooded with tarsiers retailing at less than P500 per tarsier.” Its trade and capture is illegal as the cuddly is protected by law.

The IUCN says surveys of population status, particularly to determine the tarsier’s ability to persist in non-forest areas in the long-term, are needed. The species would also benefit from tighter controls on harvest and trade.

Spurdog

The Philippines Spurdog – also found in Indonesia and the warm-temperate to tropical waters of Australia – is assessed as vulnerable based on global population declines as high as 30 percent.

It has suffered documented declines of as much as 97 percent between 1976-77 and 1996-97 in a the heavily trawled area off New South Wales, Australia.

There, total catches declined from a mean of 44.8 kilogram per hour to 1.2 kg/h during the same period.

A small number of vessels targeted dogfish with a significant bycatch of spurdogs off Western Australia during the mid-1990s. The fishery was short-lived, due to dramatic declines in catch rates after two to three years and had all but ceased by 1999.

Fishing pressure is intensive on trawl grounds around southeast Australia and lower in Western Australia where it has been taken as a bycatch in a small, short-lived demersal gillnet fishery in the mid-1990s which ceased due to rapid catch declines.

It is also caught in larger numbers at some landing sites from which deepwater fisheries operate in Indonesia and the Philippines.

Deepwater spurdogs have been targeted by fisheries off the Philippines since 1967 which have generally collapsed after 10 years of operation due to over-exploitation.

Given that unregulated deepwater fisheries are rapidly expanding off Indonesia and the Philippines, declines are only likely to continue, the IUCN observes, adding that catch levels and expanding fisheries should be monitored if fishing pressure expands further.

It is also caught commonly by demersal longline fisheries operating in deepwater in some parts of Indonesia and the Philippines. Although at present deepwater fisheries are not operating below 600 meters off Indonesia, this is unlikely to be the case for much longer.

The deep-sea fisheries in the Philippines are in many cases uncharted and unknown, and are believed to be relatively underexploited. Still, spurdogs have a documented history of wide-scale exploitation here, being targeted for their liver oil.

Fishing for dogfishes for their live oil began in 1967 in San Joaquin, Iloilo, and subsequently expanded and developed into nationwide fisheries. Spurdogs form part of the catch.

The fisheries appear to follow a typical boom-and-bust cycle, with heavy, unregulated exploitation resulting in increasing initial catches followed by collapse after about 10 years. Fisheries following this pattern have been conducted in Batangas Bay, the waters off Marinduque and as far south as Sarangani Bay in Mindanao.

So far, there are no species-specific measures in place for the spurdog. Since 2003 in Australia, vessels are required to land both the livers and carcasses of all dogfishes to enable accurate landing information to be recorded. Since 2007, fishery was closed below 700 meters to prevent targeting of deepwater species.

Butterflyfish

The Philippine Butterflyfish is classified as “Least Concern” because there have been no declines documented. It has a relatively wide distribution, apparently large population and no obvious major threats other than coral loss of which little is known.

The IUCN recommends further research on the threats and feeding behavior of this species.

The butterflyfish ranges in the coral reefs and reef slopes, from the Ryukyu Islands (Japan) and Taiwan in the north; through the Philippines; Indonesia and Malaysian Borneo; to northwestern Australia and Palau

It feeds on corals, crabs, worms and other invertebrates. Source: IUCN

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