International Journal of Marine Science, 2025, Vol.15, No.6, 320-328 http://www.aquapublisher.com/index.php/ijms 322 impact, the size of the scale is really an issue that cannot be avoided. Small-scale and community-based breeding has a small impact and high acceptance. Conversely, if large-scale and intensive systems are not managed properly, pollution, diseases and even habitat destruction may follow one after another (Zamora et al., 2018; Chary et al., 2020; Magondu et al., 2021). To expand the scale of IMTA without any problems, the key still lies in flexible management measures to act as a "balance beam". 3 Impact on Benthic Environments 3.1 Effects of sea cucumber feeding behavior on sediment structure and nutrient release Don't be fooled by the slow appearance of sea cucumbers. They are not idle during the process of turning over silt at the bottom of the sea. What they consume is not clean sand but "nutrient mud" rich in organic matter, which is exactly what they like. Sea cucumbers digest the easily decomposing parts and then discharge the treated sediment, which to some extent can be regarded as giving the sediment a "makeover". Such processes often change the structure of sediment and also bring out some stored nutrients. For instance, the release of ammonium increases significantly, which is beneficial to benthic algae - it can promote their growth (MacTavish et al., 2012; Purcell et al., 2016). However, the undigested proteins and lipids in feces are actually quite sought-after. Many other benthic animals will take over and continue to break them down and utilize them. In high-density aquaculture environments, the "scavenger" eating method of sea cucumbers is particularly crucial. They can break down excess organic matter and reduce the burden on sediment in the aquaculture system - especially when the feed input is excessive, the effect is more obvious (Pasquini et al., 2023). 3.2 Benthic eutrophication and organic matter accumulation issues Once the organic matter in the sediment accumulates too much, the system begins to malfunction. Intensive farming can easily exacerbate this eutrophication, especially when it accumulates at the bottom. Can sea cucumbers alleviate this problem? The answer is - it depends. They can indeed accelerate the rate of debris decomposition and reduce the concentrations of organic carbon and nutrients, especially at appropriate densities (Ennas et al., 2023). However, if the density is too high or the system management is unreasonable, the situation may be reversed. Not only will the problem not be alleviated, but local organic matter may also accumulate more (Namukose et al., 2016; Hou et al., 2017; Zamora et al., 2018). Therefore, "how much to put" and "how to raise" remain the key factors determining whether sea cucumbers can play a purifying role. 3.3 Bioturbation and microbial community restructuring in sediments Sediment is not dead, especially when sea cucumbers are churning inside. Their activities stir up sedimentary layers, causing changes in the REDOX environment of the sediments and also affecting the microbial composition within them (Figure 1). Some studies have found that after sea cucumbers are active, the bacterial abundance increases and the number of primary producers at the bottom decreases. Instead, those bacteria that are good at decomposing organic matter gain the upper hand (Namukose et al., 2016; Yamazaki et al., 2019). Oxygen production decreases, the number of active microorganisms in anaerobic or hypoxic environments increases, and certain functional genes also increase accordingly (MacTavish et al., 2012; Maritan et al., 2025). Such changes not only concern the microorganisms themselves, but also affect the stability and functional performance of the entire benthic system (Robinson et al., 2016; Wang et al., 2023). It is worth noting that the feeding and excretion of sea cucumbers are not "one-off". They repeatedly process the sediment in the same area, thereby selectively enriching certain microbial groups and causing a shift in the microbial composition of the sediment. This may also be a manifestation of ecosystem self-regulation (Wang et al., 2023). 4 Impact on Water Quality and Planktonic Systems 4.1 Suspended particulate matter (SPM) and water transparency variations In tropical regions, whether sea cucumbers are farmed alone or placed in a mixed system like IMTA, people have found that the water becomes clearer. This is not surprising - sea cucumbers themselves like to "eat" the organic particles that sink to the bottom, and as a result, they also carry away the suspended solids (SPM) in the water. In contrast, in ponds or systems without sea cucumber farming, the concentrations of colored dissolved organic matter
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