{"id":2614,"date":"2023-10-12T13:16:09","date_gmt":"2023-10-12T13:16:09","guid":{"rendered":"http:\/\/kambaku.net\/?p=2614"},"modified":"2023-10-12T13:16:36","modified_gmt":"2023-10-12T13:16:36","slug":"encalhe-de-krill-em-massa-intriga-cientistas-na-ilha-de-benguerra-no-bazaruto","status":"publish","type":"post","link":"https:\/\/kambaku.net\/en\/encalhe-de-krill-em-massa-intriga-cientistas-na-ilha-de-benguerra-no-bazaruto\/","title":{"rendered":"Mass stranding of Krill intrigues scientists on Benguerra Island in Bazaruto"},"content":{"rendered":"

Oct 12, 2023 <\/strong>|<\/strong> <\/mark><\/p>\n\n\n\n

An intriguing mass stranding of an unidentified species of krill, shrimp-like invertebrate animals, occurred in the northern bay of Benguerra Island, adjacent to the Bazaruto Center for Scientific Studies (BCSS) research station, and in other parts of the island.<\/p>\n\n\n\n

According to BCSS<\/a>, thousands of carcasses of these small creatures were found on the beach, covering the sand exposed during low tide. The event was quickly followed by the arrival of ants, crabs, and birds that feasted on the fresh crustaceans.<\/p>\n\n\n\n

Krill, important zooplankton organisms that serve as the primary food source for various marine megafauna species such as whale sharks, mantas, and whales, covered at least five kilometers of coastline, with a width of at least ten meters, which means the approximate coverage area was, according to BCSS, at a minimum of 50,000 square meters. As for density, the team reported an average of 3,500 carcasses per square meter.<\/p>\n\n\n\n

Although mass strandings are common, these events are still poorly understood. It is challenging to determine the reasons that may have caused the stranding, although the BCSS team hypothesizes that it may be related to the strong tidal currents that move the krill shoal from deeper waters into the Bazaruto-Benguerra channel. The tide then pushes the shoal in, resulting in the mass stranding. However, this event could be the result of a combination of factors, including currents, tides, hydrodynamics, temperature variability, global climate changes, and even oxygen supply levels in seawater.<\/p>\n\n\n\n

The tide then pushes the shoal in, resulting in the mass stranding. However, this event could be the result of a combination of factors, including currents, tides, hydrodynamics, temperature variability, global climate changes, and even oxygen supply levels in seawater.<\/p>\n\n\n\n

In the Bazaruto Archipelago reefs, krill shoals typically feed species such as sardines and other baitfish, which are then followed by pelagic fish like tuna. Mass mortality events of marine organisms are not common but have been widely reported in the literature - from jellyfish and squid to fish and various cetacean species. When occurring in coastal areas, strandings might be wind-driven or current-induced.<\/p>\n\n\n\n

On some occasions, mass strandings of marine life are caused by low oxygen concentrations, which may be indirectly depleted by a phytoplankton bloom, causing oxygen deprivation or prompting animals to swim into shallower waters. This leads to the death of marine life, and the carcasses are pushed onto the coast by currents and tides.<\/p>\n\n\n\n

Mass krill strandings are known and well-described for Antarctic beaches but are less common at lower latitudes, which makes this event interesting. This swarming species plays a crucial role in the trophic web of the world's most productive marine ecosystems, and its abundance is essential for the larger marine wildlife that relies on them. Therefore, unusual mass stranding events are always a cause for concern, but the fact that krill reproduces rapidly leaves scientists more optimistic.<\/p>\n\n\n\n

Photos: BCSS<\/p>\n\n\n\n

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