DIVERSITAS DAN DISTRIBUSI FORAMINIFERA DI SELAT BENGGALA DAN SEKITARNYA, ACEH

Suhartati M. Natsir, Singgih P.A. Wibowo

Abstract


Penelitian foraminifera di sekitar Selat Benggala belum diketahui namun telah ada penelitian dari sekitar pulau-pulau kecil di laut lepas Aceh. Penelitian mengenai keragaman dan sebaran foraminifera di perairan tersebut penting dilakukan sebagai data awal untuk interpretasi lingkungan pengendapan terkait batimetri, oseanografi, ekologi, klimatologi purba dan lain-lain. Hasil identifikasi foraminifera di sekitar Selat Benggala diperoleh 19 spesies foraminifera plangtonik dan 43 spesies foraminifera bentik. Nilai rasio foraminifera plangtonik dan foraminifera bentik (rasio P/B) relatif bervariasi berkisar antara 0 dan 81,84%. Nilai nol dijumpai di tiga stasiun yang didominasi oleh Amphistegina, Calcarina dan Heterostegina penciri lingkungan terumbu karang. Nilai rasio PB tertinggi tidak dijumpai pada stasiun dengan kedalaman tertinggi (1485 m) namun di stasiun yang berdekatan dengan pantai barat Pulau Weh pada kedalaman 101 m. Hal ini kemungkinan berkaitan dengan pola arus setempat dan morfologi dasar laut (kemiringan lereng) sehingga terjadi akumulasi spesimen foraminifera plangtonik.

Kata kunci: foraminifera, rasio P/B, kedalaman, Selat Benggala, Aceh.


Foraminiferal study from Benggala Strait is unknown but it has been studied from surrounding small islands off Aceh. The study of diversity and distribution of foraminifera from the present study area is important as the initial data for the interpretation of the environmental deposition, paleo-bathymetry, paleo-oceanography, ecology, climatology and others. This study has identified 19 planktonic foraminifera and 43 species of benthic from Benggala Strait. The ratio of benthic and planktonic foraminifera (PB ratio) are varied between 0 and 81.84%. The zero value is found in three stations that dominated by Amphistegina, Calcarina, and Heterostegina associated with coral environment. The highest value of PB ratio is not found in the deepest depth (1485 m) but in a station that is close to western coast of Weh island with 101 m water depth. It may related to local current system and seafloor morphology (slope gradient) that accumulated specimens of planktonic foraminifera.
Keywords: foraminifera, P/B ratio, water depth, Benggala Strait, Aceh.


Keywords


foraminifera; rasio P/B; kedalaman; Selat Benggala; Aceh

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DOI: http://dx.doi.org/10.32693/jgk.17.1.2019.560