Keanekaragaman Jenis-Jenis Ikan yang Toleran di Perairan Kawasan Pulau Lusi Kabupaten Sidoarjo

The Diversity of Tolerant Fish in the Coastal Waters of Lusi Island Sidoarjo Regency

Salah satu upaya pemerintah dalam menanggulangi semburan Lumpur Lapindo adalah mengalirkan lumpur melalui Sungai Porong hingga terbentuk endapan yang seiring berjalannya waktu kemudian membentuk pulau buatan yang diberi nama Pulau Lusi. Akibat adanya penumpukan lumpur di perairan kawasan Pulau Lusi tersebut dapat menurunkan kualitas perairan dan keanekaragaman organisme yang ada. Penelitian ini bertujuan untuk mendeskripsikan keanekaragaman jenis-jenis ikan yang toleran di perairan kawasan Pulau Lusi Kabupaten Sidoarjo, menjelaskan hubungan antara indeks keanekaragaman jenis-jenis ikan dengan kualitas air di Perairan Kawasan Pulau Lusi Kabupaten Sidoarjo, menjelaskan indeks kelimpahan relatif jenis-jenis ikan yang toleran di perairan kawasan Pulau Lusi Kabupaten Sidoarjo, dan mengetahui kualitas air di perairan kawasan Pulau Lusi Kabupaten Sidoarjo berdasarkan indeks keanekaragaman ikan. Penelitian ini dilaksanakan pada bulan November 2019-Februari 2020. Jenis penelitian ini adalah penelitian observasional. Pengumpulan sampel ikan dan kualitas air secara fisika dan kimia dilakukan di lima stasiun. Identifikasi ikan didasarkan pada karakter morfologi. Keanekaragaman dianalisis menurut Indeks Shannon-Wiener. Indeks kelimpahan relatif dianalisis berdasarkan Rumus Kelimpahan Odum. Hubungan antara indeks keanekaragaman jenis-jenis ikan dengan kualitas air dianalisis menggunakan regresi linier sederhana. Berdasarkan penelitian yang dilakukan di Perairan Kawasan Pulau Lusi ditemukan ikan sebanyak sebelas spesies yang dikelompokkan ke dalam sembilan famili. Hubungan antara kualitas air dengan indeks keanekaragaman ikan menunjukkan hubungan positif yaitu semakin besar nilai kualitas air juga diikuti dengan semakin besar nilai indeks keanekaragaman ikan. Nilai indeks kelimpahan relatif paling tinggi adalah pada spesies ikan Mystus nigriceps dengan presentase 50% dan paling rendah pada spesies ikan Ethmalosa fimbriata dengan presentase 3%. Nilai indeks keanekaragaman ikan di Perairan Kawasan Pulau Lusi secara keseluruhan yaitu 2.31 yang termasuk dalam kategori tidak tercemar. Sehingga dapat disimpulkan bahwa kualitas air secara fisika-kimia air di Perairan Kawasan Pulau Lusi berdasarkan indeks keanekaragaman tergolong dalam kategori tidak tercemar, karena nilai H’ ˃ 2 menurut Lee, Wang & Kuo termasuk dalam kategori tidak tercemar.

Kata kunci: keanekaragaman; toleran; ikan; Perairan Pulau Lusi

One of the government’s effort in overcoming the Lapindo mudflow is to drain mud through the Porong River to form sediments which over time form an artificial island called Lusi Island. As a result of the accumulation of mud in the waters of the Lusi Island region can reduce the quality of waters and diversity of existing organisms. The purpose of this research was to descibed the diversity of fish that are tolerant in the Coastal Waters of Lusi Island Sidoarjo Regency, explained the relationship between the diversity index of fish with water quality in the Coastal Waters of Lusi Island Sidoarjo Regency, explained the relative abundance index of toleran fish in the Coastal Waters of Lusi Island Sidoarjo Regency, and know the water quality in the Coastal Waters of Lusi Island Sidoarjo Regency based on the diversity of fish. This research was did in November 2019 - February 2020. The type of research was observational reseach. Accumulation of sample fish and physical chemical quality of the waters were taken at five station. Identification fish of water based on morphological charateristics. The diversity index was analyzed according to the Shannon-Wiener index. The relative abundance index was analyzed index was analyzed based on the Odum Abundance. The relation betweet the diversity index of fish with water quality was analyzed using simple linear regression. The result revealed that there were eleven species belonging to nine family. The relation between water quality and fish diversity index showed a positive relation which the bigger value of water quality was also followed by the bigger value of fish diversity index. The highest relative abundance index is in Mystus nigriceps fish species with 50% percentage and the lowest is Ethmalosa fimbriata with 3% percentage. The value of fish diversity in the Coastal Waters of Lusi Island Sidoarjo Regency is 2.31 which included in the uncontaminated category. So, it can be concluded the relation of fish diversity index with the physical and chemical quality of the water in the territorial waters of Lusi island Sidoarjo Regency is classified as not polluted, because the value of H ˃ 2.0 which according to Lee, Wang & Kuo is included in the uncotaminated category.

Key words: diversity, tolerant, fish, Waters of Lusi Island.