Reef Fish in the Mudflats of Kaledupa Island in Wakatobi National Park, Indonesia

Although frequently described as low-fertility or low-productivity habitat, coastal mudflats serve as important feeding grounds for fish. Many fish species from adjacent coral reefs, seagrass beds, or mangroves foraging periodically in mudflats. Because of this foraging behaviour, some local fishermen are known to utilize the mudflats to catch fish. However, the impact of this catching activities to the ecosystem has not been fully discovered. An examination of the fish community structure and levels of environmental stress had carried out in the mudflat ecosystem of the coast of Kaledupa Island in Wakatobi National Park (WNP), Indonesia. Two mudflat study sites were selected from the shore of Balasuna and Tampara villages located between mangroves and coral reefs. Data were sampled from the fish catch of local fishermen using fish fences (sero) installed in each mudflat area. Fish community structure was analyzed using diversity index and index of relative importance (IRI). ABC curves and species exploitation rate were used to assess the local environmental pressure. A total of 74 fish species were recorded from the mudflats of Kaledupa, which was found to be dominated by reef-associated fish species, comprising 63 species and accounting for 85% of the total catch. Additionally, although both sites had relatively high reef fish diversity, the obtained Clarke’s W-statistic values were approximately 0, indicating that the local fish communities presented moderate levels of disturbance. Three out of five fish species with the highest IRI values were found to be over-exploited, namely Siganus canaliculatus, Lethrinus ornatus, and Lethrinus variegatus

Lobster Air Tawar Spesies Asing Invasif

Perairan tawar Indonesia cocok untuk beberapa spesies perairan, baik berasal dari dalam maupun luar negeri. Khusus spesies asing masuk Indonesia dapat melalui perdagangan atau penelitian. Pada spesies asing yang masuk Indonesia tersebut, terdapat lobster air tawar yang termasuk spesies yang invasif. Lobster air tawar yang ditemukan di berbagai lokasi yang diteliti di Yogyakarta berbeda-beda jenisnya. Setidaknya tercatat tiga jenis lobster yang ditemukan di tempat-tempat itu yakni jenis Cherax quadricarinatus (red claw), C. destructor (yabbie), dan Procambarus clarkii (red swamp crayfish). Lobster air tawar hingga akhir-akhir ini masih merupakan komoditas perikanan budidaya yang menarik. Harga jualnya yang cukup tinggi, teknik budidayanya yang relatif mudah dan sederhana, serta pasarnya yang masih terbuka lebar, merupakan beberapa faktor yang menarik minat para pembudidaya. Keterbatasan kebijakan pada level daerah turut mempercepat dan mempermudah proses penyebaran lobster air tawar ini. Pelepas liaran spesies asing, apalagi yang bersifat invasif, bagi ekosistem alami setempat bisa berdampak serius, akan tetapi nampaknya masih dianggap sebagai hal yang biasa oleh masyarakat kebanyakan. Dengan demikian, diperlukan peningkatan pengetahuan dan pemahaman masyarakat terhadap risiko dan dampak dari keberadaan biota invasif di perairan umum. Namun kesediaan masyarakat di atas untuk berpartisipasi dalam pengawasan, paling tidak, telah dapat menjadi modalitas dalam mengembangkan program pengendalian spesies asing invasif di tingkat loka