Paus Biru

BERBAGI RUANG DENGAN HEWAN LIAR in nature is one of the greatest gifts life has to offer. Maybe you’ve locked eyes with an orangutan in Borneo, or perhaps you’ve watched a clownfish gently tend its eggs on a reef. You may have spied an army of leafcutter ants marching plant clippings back to its colony or peered over the bow of a boat only to catch the gaze of a dolphin. 

Tidak peduli ukuran makhluk yang Anda temui atau kelangkaan spesiesnya, setiap kesempatan untuk membuka jendela ke dalam keberadaan sesama penghuni bumi ini adalah sebuah keistimewaan. 

Lingkungan bawah air memperkuat keistimewaan tersebut. Sebagai mamalia darat, kita membutuhkan sedikit bantuan untuk bertahan hidup di dalam air, bahkan untuk waktu yang relatif singkat. Hambatan ini sangat mengurangi jumlah interaksi dekat yang dilakukan manusia dengan satwa laut, membuat setiap pertemuan menjadi lebih bermakna. Pertemuan dengan mamalia laut membuat fenomena tersebut menjadi sangat nyata karena kemungkinan untuk berbagi momen di bawah air dengan makhluk laut ini sangat rendah. 

Berada di hadapan paus biru mungkin merupakan salah satu pengalaman yang paling menyentuh hati di Bumi, dan sangat beruntung memiliki kamera untuk mengabadikan momen tersebut adalah definisi tak ternilai harganya.     

Paus biru (Balaenoptera musculus) bukan hanya hewan terbesar yang hidup saat ini, tapi juga hewan terbesar yang pernah hidup di Bumi. Kita sangat beruntung bisa hidup di masa yang sama dengan raksasa samudra ini.

It is difficult to imagine just how huge these whales are until you’re in the water with them. They weigh as much as 200 tons and typically grow to 80 to 90 feet long. A 2021 study by Stanford University indicates that in a single day adult blue whales can consume between 10 and 20 tons of plankton, and krill is their primary food source. 

Classified as a rorqual — the largest group of baleen whales — this whale has a huge mouth filled with up to 400 baleen plates, which it uses to filter plankton from the seawater. They feed by gulping gigantic volumes of water containing krill into their mouths and then forcing the water out while plankton remains trapped in the baleen. 

Blue whales inhabit all the world’s oceans except the Arctic, and most undertake monumental migrations toward the poles in the summer and the equator in the winter. They can produce loud and low-frequency noises that allow them to communicate with one another over vast distances. Their calls can reach 188 decibels — louder than a jet engine — and travel up to 1,000 miles. 

Their average life span is between 80 and 90 years, but the oldest recorded blue whale was estimated to be 110 years old. They are one of Earth’s longest-lived animals and as such have a correspondingly low reproductive rate. They reach sexual maturity between 5 and 15 years old, and females give birth to a single calf once every two to three years after a gestation period of about one year. Calves can weigh up to 3 tons and measure nearly 25 feet at birth. 

Karena gaya hidup mereka yang sangat bermigrasi, melacak mereka dan mendapatkan perkiraan yang akurat tentang populasi mereka adalah hal yang sulit. Populasi paus biru saat ini diperkirakan berjumlah 10.000 hingga 25.000 ekor di seluruh dunia. Daftar Merah Persatuan Internasional untuk Konservasi Alam (IUCN) mengklasifikasikan mereka sebagai terancam punah, sebuah sebutan yang dihasilkan dari eksploitasi brutal selama seabad untuk mendapatkan minyak mereka. Populasi historis paus biru hampir punah pada pertengahan abad ke-20, tetapi mereka akhirnya dilindungi dari perburuan paus komersial pada tahun 1966 oleh Komisi Penangkapan Ikan Paus Internasional, yang menempatkan moratorium pada praktik tersebut 20 tahun kemudian. 

Recovery is a slow process, but we are seeing progress. With important rules and regulations in place, blue whales globally are now up to between 3 percent and 11 percent of their historical population. They are gradually rebounding, and many management practices and fishing regulations now fully protect them, but promoting these blue giants’ further protection and conservation is critical.

Unfortunately, the oceans contain far more threats than when whalers roamed the high seas. Blues must contend with rampant marine debris, ship strikes, intense noise pollution, and a declining food supply due to warming waters and commercial krill use, making the whales’ continued recovery tenuous at best. 

This species is rebounding much slower compared with other species — such as gray, humpback, and fin whales — since the end of large-scale commercial whaling, and ship strikes may be a significant factor. 

“Only a small proportion of large whale mortality is documented as strandings because most large whales sink or do not wash ashore,” reports the Cascadia Research Collective, a nonprofit founded by research biologist John Calambokidis. “True mortality has been estimated to be at least 10 times higher than suggested by the documented strandings.” 

Calambokidis dihormati secara luas atas kontribusinya terhadap penelitian dan konservasi paus. Penelitian jalur pelayarannya berhasil mengubah rute kapal yang melakukan perjalanan ke pelabuhan California untuk menjauhkan mereka dari tempat paus berkumpul. 

“I’ve focused not only on doing the research to reduce ship strikes but also working with industry and government agencies to implement changes,” Calambokidis said. While the shifts are a good start in reducing the incidence of strikes, he said more still needs to be done, including slowing down the vessels.

Marine debris is another major issue for blue whales, one that has reached plague proportions in our world’s waters. Human garbage big and small has infiltrated and polluted every marine habitat from the equator to the poles. Blue whales encounter marine debris in many forms, including microplastics, massive ghost fishing nets, and everything in between. 

Makalah yang diterbitkan dalam jurnal Komunikasi Alam pada tahun 2022 memperkirakan bahwa seekor paus biru dapat mengonsumsi hingga 10 juta keping plastik mikro setiap hari selama musim makan utamanya. Jumlah tersebut setara dengan hampir 100 pon plastik setiap harinya. Namun, para penulis studi melaporkan bahwa hanya 1 persen plastik yang ditelan paus balin yang berasal langsung dari air yang disaring dari mulut mereka. Mangsa yang dimakan paus telah menelan 99 persen lainnya.

Another problem results when old, broken, or entangled fishing gear is dumped in the ocean, creating ghost fishing gear. These ghost nets are the most harmful form of marine debris and can drift with ocean currents for years or even decades, leaving a trail of destruction in their wake. As many as 60 percent of the blue whales in Canada’s Gulf of St. Lawrence have had interactions with fishing ropes and nets based on scarring shown in drone photographs. Due to their size, blues are usually able to break free and survive, but that certainly doesn’t mean they haven’t suffered undue trauma and stress. This obstacle is not negligible for a species that is already struggling to survive. 

Ini bukanlah satu-satunya kesulitan yang dihadapi paus biru, tetapi karena kesulitan yang melekat dalam mempelajari hewan pelagis raksasa ini, hanya ada sedikit data konklusif yang dapat merinci dampak negatif spesifik dari ancaman lain seperti polusi suara, peningkatan suhu air, dan pengasaman laut. Faktor-faktor ini memiliki dampak negatif yang dapat diukur pada berbagai spesies laut lainnya, sehingga masuk akal jika bahaya yang sama juga dapat menyebabkan stres pada paus biru.

Banyak hal yang kita lakukan atas nama kemajuan justru berbahaya bagi dunia dan kehidupan yang ditopang olehnya, termasuk diri kita sendiri. Paus layak mendapatkan perlindungan dan penghormatan bukan hanya karena nilai intrinsiknya, tetapi juga karena mereka memainkan peran penting dalam fungsi planet kita. 

Michael Fischbach, executive director of the Great Whale Conservancy, explains that whales help stimulate plankton production, which in turn produces more oxygen to offset the impacts of climate change. “For the health of the oceans, we really need more whales,” he said. 

A report published by the International Monetary Fund in 2019 supports that statement: “When it comes to carbon, one whale is worth thousands of trees. Whales help to regulate the climate by enhancing phytoplankton growth at the ocean surface, which captures 37 billion tons of CO₂ [carbon dioxide] per year.”      

Blue whales are many things: majestic, massive, strong, fragile, mysterious, endangered, and critical. But most of all, they are worthy — worthy of lives free from the myriad anthropogenic hazards we have thrust upon them. We owe it to them, and we owe it to ourselves. We must yet again work to save the whales, not just for their sake but for ours as well. AD

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© Penyelam Siaga - Q3 2023