International Journal of Molecular Ecology and Conservation, 2025, Vol.15, No.4, 163-174 http://ecoevopublisher.com/index.php/ijmec 1 68 whale's descent. From the accumulation stage when large scavengers tear whale meat, to the opportunistic stage when crustaceans prey on small worms, and then to the energy stage when some predatory polychetes (such as worms of the Hesionidae family) prey on filter-feeding crustaceans (Shimabukuro and Sumida, 2019), these predatory behaviors help regulate the population size. Maintain the balance of the community structure. The temporary visits of top predators also play a role - deep-sea fish, sleeping sharks, etc. occasionally return to whale lands to prey on small animals, further transmitting energy upwards (Tian et al., 2024). Symbiosis: Whale falls provide a stage for various symbiotic relationships. A typical example is the chemogenic stage of nutritional symbiosis. Symbiosis such as mussel - sulfur-oxidizing bacteria and Osedax- heterotrophic bacteria makes it possible for the host to obtain nutrients in extreme environments (Shimabukuro and Sumida, 2019; Silva et al., 2021). In addition, there are spatial symbiosis and attachment relationships. For instance, some barnacles attach to whale bones to filter food, and attached barnacles can provide hiding places for small crustaceans. These complex interaction relationships enable whale fall communities to have a certain self-sustaining function. Even if external nutrition decreases, internal energy can still partially circulate. 4.4 Regulatory effects of environmental factors on communities The physical and chemical factors of the Marine environment also play an important regulatory role in the succession of whale fall communities. Water depth and temperature can affect the decomposition rate and community composition. In shallower waters (such as 500~1000 meters), where the temperature is higher and scavengers are more active, the soft tissue decomposition of whales is faster, the meat accumulation stage is shorter, and the duration of the subsequent energy depletion stage is also shorter (Zhou et al., 2020). Ocean currents and oxygen supply: The intensity of ocean currents affects the diffusion of nutrients around whale falls. Under strong current conditions, the organic matter of whale falls may be dispersed and diluted more quickly, and the opportunistic stage is not very obvious. In weak current basins, nutrient enrichment is concentrated around the bones, which is conducive to the emergence of a large number of settlers (Li et al., 2022). Sediment type: The seabed substrate affects the settlement patterns of whale fall organisms. In soft and muddy sedimentary environments, whale bones are prone to partial burial, sulfides accumulate within the sediments, and opportunistic organisms mostly burp for food. In hard or rocky environments, whale bones are exposed in water, attracting more attached filter-feeding organisms to enter the late stage (Bolstad et al., 2023). Geographical and biogeographic factors should not be ignored either. The differences in species pools among different ocean basins will lead to differences in community composition. For example, the species richness of Osedax is high in whale falls in the North Pacific, while the diversity of bone-eating worms is relatively low in whale falls in the Southern Ocean, but many invertebrate groups specific to cold water have emerged (Stauffer et al., 2022; Bolstad et al., 2023). This reflects the restrictive effect of regional species supply on community structure. 5 The Connection Between Whale Falls and Deep-Sea Ecosystems 5.1 Whale falls as deep-sea "ecological hotspots" Whale falls are regarded as important "ecological hotspots" or "nutrient islands" in the deep sea and play a significant role in enhancing local biodiversity. Whale falls gather a variety of scavenging and opportunistic species from the surrounding wide area, allowing them to appear simultaneously in a small area. Whale falls have also given rise to a large number of new species. Scientists have discovered over 100 species that set new scientific records on global whale falls, many of which are considered "desperate" creatures highly specialized in the whale fall environment (Souza et al., 2021). In addition, whale falls have significantly increased the functional diversity of deep-sea ecosystems. Originally, deep-sea benthic communities mainly decomposed sedimentary organic matter, while whale falls simultaneously contain multiple nutritional functional groups such as filter eaters, scavengers, and chemoautotrophs, coexisting in the same system (Li et al., 2022). 5.2 Spillover effects on surrounding habitats and neighboring communities The impact of whale falls is not confined to the small area where their skeletons are located; there is also a certain "spillover effect" on the surrounding deep-sea habitats and neighboring communities. The nutrient sources provided by whale falls overflow into the surrounding sedimentary environment, benefiting the adjacent seabed
RkJQdWJsaXNoZXIy MjQ4ODYzNA==