The whale beaching phenomenon, What caused it?

Whales are one of the marine mammals that carry out routine migration activities. The migration journey is carried out from cold northern waters to warmer tropical waters. Initially, researchers suspected that the mating season was a factor that triggered whales to migrate. Before the wedding season, whales will migrate towards warmer waters to give birth and get away from predators. However, based on the latest research, It turns out that whale migration trips are not just for breeding. Launching from Science Mag, the researchers discovered that the whales' migratory journeys are carried out to shed the mammal's outer skin cells. In cold waters, The microscopic diatom layer on the whale will thicken and skin regeneration will be very slow, pushing the whale towards warmer waters.

Beached whale

The phenomenon of whales stranding during migration has increased in recent years. Most stranded whales die and only a few are successfully returned to the sea. as recently happened in Indonesian waters. As much 52 Short-finned Pilot Whale (Globicephala macrorhynchus) stranded on Modung Beach, Bangkalan, East Java, on Friday (19/2/2021). The whale is thought to have come from Australian waters and migrated through Indonesian waters. This phenomenon has actually been happening since Thursday (18/2/2021), Most of the whales were still alive and were successfully pushed by the fishermen back into the sea. But at night, dozens of whales were again stranded on the beach. The receding sea water conditions make it difficult for whales to swim back to the sea. After the evacuation process is carried out, only 3 The whale's tail was still alive and was successfully returned to the sea.

A similar incident also occurred on the coast of New Zealand on Monday (22/2/2021). New Zealand Department (DOC) said that 49 Long-finned Pilot Whale (Globicephala melas) found stranded in the distant Farewell Spit area 90 kilometers north of the tourist town of Nelson on the South Island. As much 60 People try to keep the whales alive until they can swim back into the sea at high tide. Finally as much 40 The whale's tail was saved. Within a period of time 15 last year, at least this phenomenon has occurred as much 10 times in the area. Even in years 2017, 700 The whale's tail was almost stranded with 250 One of the whales eventually died.

Navigation problems

When migrating, In general, whales will pass through the same path. The whale's ability to remember the path it has taken is supported by the presence of its biomagnetite. Biomagnetite is a substance found in the retina of whale cetaceans and functions as a magnetic sense that helps whales in knowing the direction of movement. Disturbances in whale navigation due to geomagnetic fields near the coast as well as magnetic fields perpendicular to land are thought to play a role in mass whale strandings in certain coastal areas. The phenomena of storms and sunspots that occur every few years also result in quite large changes in the Earth's magnetic field, so it has a big influence on the migration routes of whale species that use geomagnetism as natural navigation.

Some types of whales have group leaders when migrating. If the leader loses orientation due to magnetic field disturbances or unhealthy body conditions, then the accompanying group will follow in the wrong direction. other than that, attacks from predators, extreme weather, and movement following natural food towards land can also cause whales to become stranded. Apart from these natural factors, underwater noise generated from ships, icebreaker, drilling rig, and military sonar can also massively disrupt the orientation and communication of marine mammals. The higher density of water compared to air causes the sound produced to travel five times faster than in air. Sounds that have more intensity than 200 decibels can trigger the formation of gas waves in the blood vessels of marine mammals. This causes the blood supply to be disrupted, causing death.

Source :

• https://www.inews.id/multimedia/photo/51-paus-pilot-mati-terdampar-di-bangkalan-dikubur-massal/1/2
• https://news.detik.com/internasional/d-5400197/kasihan-puluhan-paus-terdampar-di-teluk-selandia-baru?_ga=2.219314265.1779396844.1614052872-462031964.1589882104
• https://www.republika.co.id/berita/qoxfrl328/analisis-pakar-soal-terdamparnya-52-paus-pilot-di-bangkalan
• https://sains.kompas.com/read/2020/02/22/193200623/demi-kulit-yang-sehat-mungkin-ini-alasan-migrasi-paus-pembunuh?page=all
• https://www.kompas.com/tren/read/2020/10/17/055737265/mengapa-paus-dan-lumba-lumba-bisa-terdampar-ini-beberapa-sebabnya?page=all

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