Kemunculan dan Tingkah Laku Hiu Paus (Rhincodon typus) Berdasarkan Karakteristik Lingkungan di Perairan Pantai Botubarani, Gorontalo

Abstract

Hiu paus merupakan megafauna yang tinggal di lautan beriklim tropis dan sub-tropis hangat sebagai pemangsa organisme berukuran kecil dengan cara menyaring air laut atau filter feeder. Faktor lingkungan seperti suhu permukaan laut (SPL), salinitas (Sal), klorofil-a (kl-a), arus permukaan laut (arus), dan kelimpahan biota laut tertentu, seperti zooplankton dan ikan pelagis kecil, berperan dalam kemunculan hiu paus di perairan pesisir. Tingkah laku hiu paus muncul di permukaan laut dekat dengan pesisir pantai dapat mendorong aktivitas wisata yang membawa dampak antropogenik. Hiu paus terpengaruh aktivitas antropogenik umumnya menunjukkan tingkah laku tertentu, yang dapat ditinjau dari caranya bergerak saat berada di area wisata maupun berinteraksi dengan manusia di lingkungan tersebut. Kemunculan hiu paus di perairan Pantai Botubarani telah diketahui sejak tahun 2016 dan mendorong berkembangnya aktivitas wisata lokal. Tujuan penelitian ini adalah (1) Menganalisis faktor oseanografi yang mempengaruhi kemunculan hiu paus di perairan Pantai Botubarani, (2) Menganalisis dampak aktivitas antropogenik terhadap perilaku hiu paus, dan (3) Menjelaskan hubungan antara faktor oseanografi dan aktivitas antropogenik terhadap kemunculan dan tingkah laku hiu paus. Data kemunculan hiu paus selama tiga tahun terakhir (Juni–Desember 2022, Januari–Desember 2023, dan Januari–Juli 2024) diperoleh dari Balai Pengelolaan Sumberdaya Pesisir dan Laut (BPSPL) Makassar. Data tingkah laku diperoleh dari pengamatan langsung terhadap individu hiu paus di Pantai Botubarani menggunakan stereo-Diver Operated Video (DOV) (Feb-Apr 2024). Pengamatan pergerakan hiu paus di area wisata dan tingkah laku hiu paus saat berinteraksi dengan wisatawan mengacu pedoman dari Martin (2007). Ada tiga perilaku terganggu yang jadi fokus kajian ini, yaitu abrupt changes, banking, dan shuddering. Data beberapa parameter oseanografi (SPL, salinitas, klorofil-a, arus permukaan laut) diperoleh dari website Marine Copernicus untuk periode Juni 2022–Juli 2024. Analisis statistik deskriptif digunakan untuk mengkaji pola kemunculan hiu paus dengan parameter oseanografi lingkungan, sedangkan Principal Component Analysis (PCA) digunakan untuk mengidentifikasi parameter oseanografi yang lebih utama mempengaruhi kemunculan hiu paus pada periode tertentu.

Kemunculan hiu paus di perairan Pantai Botubarani pada tahun 2022, 2023, dan 2024 secara berturut-turut adalah 224, 337, dan 219 kemunculan. Hasil tiga bulan pemantauan langsung mendapati empat individu yang teridentifikasi positif sebagai WS-GT-01, WS-GT-02, WS-GT-03, dan WS-GT-04. WS-GT-01 tidak menunjukkan tingkah laku terganggu selama teramati di zona interaksi wisata hiu paus, sedangkan WS-GT-02 menunjukkan satu kali abrupt changes. WS GT-03 menunjukkan 5 kali abrupt changes, banking (1), dan shuddering (13 kali), kemudian WS-GT-04 teramati menunjukkan seluruh perilaku terganggu oleh aktivitas wisata karena tercatat menunjukkan tujuh kali abrupt changes, banking, dan shuddering. Kemunculan hiu paus di lokasi wisata juga berasosiasi dengan tingkah laku makan atau berburu mangsa alami di zona interaksi wisatawan, karena ada aksi memanggil dan menebar umpan oleh pemandu wisata.

Nilai rata-rata musiman dari beberapa parameter lingkungan perairan Pantai Botubarani disesuaikan dengan durasi kemunculan hiu paus, sehingga diperoleh rata-rata suhu permukaan laut (SPL), salinitas (Sal), klorofil-a (Kla) dan kecepatan arus permukaan (arus) pada Musim Barat (*MB) secara berturut-turut adalah 20.03 °C, 33.35 PSU, 0.135 mg/m3, dan 0.16 m/s dengan rata-rata kemunculan hiu paus 29.45 kemunculan/bulan. Pada Musim Peralihan I, nilai rata-rata SPLMP1 adalah 30.13 °C, SalMP1 33.68 PSU, KlaMP1 0.14 mg/m3, ArusMP1 0.13 m/s, dan 21.17 kemunculan hiu paus. Nilai rata-rata beberapa parameter oseanografi fisik selama Musim Timur (*MT) umumnya lebih rendah dibandingkan periode sebelumnya, yaitu SPLMT 29.78 °C, SalMT 33.61 PSU, dan arusMT 0.12 m/s, kecuali parameter klorofil-a permukaan dan kemunculan hiu paus yang lebih tinggi (KlaMT 0.15 mg/m3) dan 28.22 kemunculan. Kemunculan hiu paus dan nilai rata-rata klorofil-a permukaan selama Musim Peralihan 2 lebih rendah dibandingkan Musim Timur (28.17 kemunculan/bulan, KlaMP2 0.14 mg/m3) yang berlangsung saat nilai rata-rata suhu dan salinitas mencapai puncak tahunannya (SPLMP2 30.43 °C, SalMP2 33.82 PSU) sedangkan rata-rata kecepatan arus permukaan paling rendah (arusMP2 0.08 m/s) dibandingkan periode lainnya. Kemunculan hiu paus di perairan Pantai Botubarani menunjukkan penurunan dari Musim Barat ke Musim Peralihan 1 dan naik kembali pada Musim Timur. Hasil analisis PCA menunjukkan bahwa parameter oseanografi lingkungan yang lebih utama memengaruhi kemunculan hiu paus di Pantai Botubarani adalah arus permukaan laut dan konsentrasi klorofil-a permukaan.

Whale sharks are megafauna that inhabit tropical and warm subtropical seas as filter feeders that prey on small-sized organisms by filtering seawater. Environmental factors such as sea surface temperature (SST), salinity (Sal), chlorophyll-a (Chl-a), ocean surface currents (currents), and the abundance of certain marine biota such as zooplankton and small pelagic fish play a role in the appearance of whale sharks in coastal waters. The behavior of whale sharks surfacing near the coast can promote tourism activities, which in turn may cause anthropogenic impacts. Whale sharks affected by human activities generally exhibit specific behaviors, which can be reviewed by observing how they move in tourist areas and how they interact with people in that environment. The appearance of whale sharks in the waters of Botubarani Beach has been known since 2016 and has driven the growth of local tourism. This study aims to (1) analyze oceanographic factors influencing whale shark appearances, (2) assess the impact of anthropogenic activities on their behavior, and (3) explain the relationship between these two influences on the whale sharks’ presence and behavior. Whale shark sighting data from the past three years (June–December 2022, January–December 2023, and January–July 2024) were obtained from the Coastal and Marine Resources Management Center (BPSPL) Makassar. Behavioral data were collected through direct observation of individual whale sharks at Botubarani Beach using stereo-Diver Operated Video (DOV) (Feb–Apr 2024). Observations of whale shark movements in tourist areas and their behavior when interacting with tourists referred to the guidelines by Martin (2007). Three types of disturbed behavior were the focus of this study: abrupt changes, banking, and shuddering. Several oceanographic parameters (SST, salinity, chlorophyll-a, surface current velocity) were obtained from the Marine Copernicus website for the period June 2022–July 2024. Descriptive statistical analysis was used to assess the pattern of whale shark appearances alongside environmental oceanographic parameters, while Principal Component Analysis (PCA) was used to identify the most influential oceanographic parameters affecting whale shark appearances during specific periods.

The number of whale shark appearances in the waters of Botubarani Beach in 2022, 2023, and 2024 were 224, 337, and 219 sightings respectively. Three months of direct observation identified four individuals, positively marked as WS-GT-01, WS-GT-02, WS-GT-03, and WS-GT-04. WS-GT-01 did not exhibit any disturbed behavior during observations in the whale shark tourism interaction zone, while WS-GT-02 showed one instance of abrupt change. WS-GT-03 showed five instances of abrupt changes, one instance of banking, and 13 shuddering events. WS-GT-04 was observed exhibiting all three disturbed behaviors due to tourism activities, with seven abrupt changes, banking, and shuddering recorded. The appearance of whale sharks at the tourism site was also associated with feeding or foraging behavior in the tourist interaction zone, triggered by guides calling and scattering bait.

The seasonal averages of several environmental parameters in the waters of Botubarani Beach, aligned with the whale shark appearance periods, were as follows: sea surface temperature (SST) at 20.03 °C, salinity at 33.35 PSU, chlorophyll-a at 0.135 mg/m³, and surface current speed at 0.16 m/s, with an average of 29.45 whale shark sightings per month. During the First Transitional Season, the average values were SST 30.13 °C, Sal 33.68 PSU, Chl-a 0.14 mg/m³, current 0.13 m/s, and 21.17 whale shark appearances. In the Eastern Season, the average values for physical oceanographic parameters were generally lower compared to the previous period: SST 29.78 °C, Sal 33.61 PSU, and current 0.12 m/s, except for surface chlorophyll-a and whale shark appearances, which were higher (Chl-a 0.15 mg/m³; sightings 28.22). During the Second Transitional Season, both whale shark appearances and surface chlorophyll-a values were lower compared to the Eastern Season (28.17 sightings/month, Chl-a 0.14 mg/m³), while SST and salinity reached their annual peak values (SST 30.43 °C, Sal 33.82 PSU), and surface current speed was the lowest (0.08 m/s) compared to other periods. Whale shark appearances in the waters of Botubarani Beach showed a decrease from the Western Season to the First Transitional Season and increased again during the Eastern Season. PCA results indicate that the most influential environmental oceanographic parameters on whale shark appearances at Botubarani Beach are surface current velocity and surface chlorophyll-a concentration.