The decline of native fishes and fisheries and the rise of aquaculture in lakes and rivers in the Philippines
MetadataShow full item record
This paper reviews historical and recent data on biodiversity, fisheries, exotic fishes, and aquaculture in Philippine lakes and rivers. The country's lakes and rivers are poor in primary freshwater fishes because the Philippines' only connection with the Asian mainland had been through land bridges between Borneo, the Sulu islands, Mindanao, Palawan and Mindoro - in which islands endemic carps have evolved. Philippine lakes and rivers instead have secondary freshwater fishes such as gobies, migratory marine fishes such as mullets, and some snails, clams, and prawns. Most lakes and rivers have been severely degraded and their biodiversity reduced by siltation, pollution, overfishing, and the establishment of exotic fishes from other countries or elsewhere in the country. Many fishes first described in the Philippines in 1910-1940 by Seale, Herre, and Filipino ichthyologists have not been collected in recent years. The Laguna de Bay fishery in the early 1960s was largely dependent on the 'ayungin' Therapon plumbeus, 'biyang puti' Glossogobius giurus, and the 'kanduli' Arius manilensis that together comprised 95% of the annual 83,000 mt; another 19,000 mt came from shrimps and 245,000 mt from snails. Fishing and snail-dredging were so intense that catches declined and the whole lake fishery collapsed around 1970. After the collapse, the primary production of the lake increased and milkfish and tilapia became natural choices for aquaculture. Lake Lanao became famous for its species flock of 18 endemic carps, but these are now extinct, except perhaps two species. In 1963, these carps contributed 981 mt to the fishery, other native fishes 269 mt, shrimps and snails 257 mt, and introduced fishes 479 mt. Twenty years later, endemic carps have made up only 92 mt, native fishes 141 mt, shrimps and snails 164 mt, and introduced fishes 312 mt of the harvest from the lake. The 'kadurog' G. giurus, probably stocked in the lake with milkfish larvae in 1955, proliferated in the 1960s and apparently drove the endemic carps to extinction. The 'katolong' Hypseleotris agilis was first seen in the lake in 1977 and has since outcompeted the 'kadurog'. In Lakes Taal and Naujan, migratory marine fishes have been caught by fish corrals set across the outlets, but the catch along Pansipit River has fallen since the turn of the century and that in Butas River fell from 62 mt in 1977 to 17 mt in 1983. Catches of the endemic sardine Harengula tawilis in Lake Taal fluctuated between 4,400 mt in 1983 to 11,300 mt in 1990 and 1,400 mt in 1994. Cage culture of tilapia and milkfish has been going on in Lake Taal for 10 years. In Lakes Buhi and Bato, the endemic 'sinarapan' Mistichthys luzonensis almost disappeared due to fine-net fishing and tilapia stocking; catches have been 50-90 mt in 1983-93 but zero in 1994.
Bagarinao, T. U. (2001). The decline of native fishes and fisheries and the rise of aquaculture in lakes and rivers in the Philippines (Abstract only). In C. B. Santiago, M. L. Cuvin-Aralar & Z. U. Basiao (Eds.), Conservation and Ecological Management of Philippine Lakes in Relation to Fisheries and Aquaculture (p. 151). Southeast Asian Fisheries Development Center, Aquaculture Department, Iloilo, Philippines; Philippine Council for Aquatic and Marine Research and Development, Los Baños, Laguna, Philippines; and Bureau of Fisheries and Aquatic Resources, Quezon City, Philippines.
PublisherSEAFDEC Aquaculture Department; Philippine Council for Aquatic and Marine Research and Development; Bureau of Fisheries and Aquatic Resources
Culture effects; Ecosystem disturbance; Endemic species; Fish culture; Fishery resources; Introduced species; Man-induced effects; Nature conservation; Overfishing; Resource conservation; Rivers; Species extinction; Lakes; Arius manilensis; Chanos chanos; Cyprinidae; Decapoda; Gastropoda; Glossogobius giurus; Hypseleotris agilis; Leiopotherapon plumbeus; Mistichthys luzonensis; Oreochromis; Therapon plumbeus; Philippines
Showing items related by title, author, creator and subject.
Translocation of the clupeid Sardinella tawilis to another lake in the Philippines: A proposal and ecological considerations. AC Mamaril - 2001 - SEAFDEC Aquaculture Department; Philippine Council for Aquatic and Marine Research and Development; Bureau of Fisheries and Aquatic ResourcesThe dwindling commercial catch of Sardinella tawilis (Clupeidae), locally known as 'tawilis', reported in recent years by local fisher folk in Lake Taal, Batangas, Philippines, could be a result of the interaction of factors such as over fishing, destructive fish-capture techniques, changes in water quality, and others. Like the rest of the handful of endemic freshwater fish species in the Philippines, S. tawilis is threatened with depletion of its stocks, if not with extinction in the near future. A conservation strategy that could be considered is the translocation of 'tawilis' to another lake in the Philippines, whose ecological features closely resemble those of Lake Taal and where 'tawilis' would receive socio-economic and cultural acceptability. Cases of clupeid introductions - natural and man-made, successes and failures - are presented from published literature. Special attention is given to the case of a well-planned trans-country (Thailand-to-Indonesia) attempt to introduce a clupeid fish. The broader questions of biodiversity, endemicity, conservation, and fish community structure in Lake Taal (and elsewhere) must be underpinned by sound basic taxonomy and ecology.
Conference paperK Fukusho - In TU Bagarinao & EEC Flores (Eds.), Towards sustainable aquaculture in Southeast Asia and Japan: Proceedings of the Seminar-Workshop on Aquaculture Development in Southeast Asia, Iloilo City, Philippines, 26-28 July, 1994, 1995 - SEAFDEC Aquaculture DepartmentAquaculture production in Japan in 1993 was 1,351,000 tons, 15.6% of the total fisheries production. About 93.6% came from mariculture and 6.4% from freshwater aquaculture. The per cent contribution of aquaculture to total production has increased in recent years but partly because marine fisheries,especially of sardine and pollack, have decreased. Aquaculture has reached a plateau, and decreased slightly between 1992 and 1993. Diverse marine and freshwater species are cultured in Japan — various fishes, crustaceans, mollusks, seaweeds, sea squirt, sea urchin, and others. Research and development in mariculture focus on finding substitutes for animal protein in feeds, improvement of fish quality, protection of the culture environment, use of offshore floating culture systems, and protection from diseases. Research in freshwater aquaculture has expanded to include recreational fishing, the propagation and preservation of endangered species, and the construction of fish ladders for salmonids and other migratory species.
ArticleVGV Paller, MNC Corpuz & PP Ocampo -
Philippine Journal of Science, 2013 - Science and Technology Information InstituteThree stream sections (upstream, midstream, and downstream) of Tayabas River, Philippines were surveyed during the wet and dry seasons of 2010 to evaluate the poorly known status of freshwater fish assemblages. The study collected a total of 1,070 individuals comprising 15 species, 13 genera, and 8 families. The three most abundant groups were poeciliids (61.85%), gobiids (26.16%), and cichlid (5.51%). Shannon-Weiner’s diversity indices ranged from 1.270 to 2.171. Relatively high Shannon evenness indices (0.653–0.846) and low Simpson’s dominance values (0.142–0.322) were calculated implying a fairly equitable distribution of niche space for dominant and non-dominant fishes. Significant change on fish assemblage in longitudinal gradient was observed (p<0.05), being the most diverse fish assemblage registered in the upstream. Species richness is mostly composed of native fish species (10 species) and mainly represented by stream gobiids (six species). The downstream, however, had the highest cumulative abundance, in which the larger proportion was from introduced species. Also, wet season had considerably more fish species and individuals relative to dry season (p<0.05). This significant spatio-temporal differences in fish assemblage data were evaluated by multivariate analyses (p<0.05). Canonical correspondence analysis identified the depth (seasonal water level fluctuations), vegetation growth, and dissolved oxygen concentrations (in order of importance) as the most influential environmental parameters affecting fish assemblage structure. Also, climatic stress (prolonged drought) and anthropogenically-induced habitat alteration could negatively affect the integrity of freshwater fishes within the river. The study suggests extensive management programs of the river for the protection of native fish species.