Seafood processing involves preparing seafood for distribution and consumption through steps such as washing, chilling, gutting, filleting, cooking, freezing, and packaging (Murali et al., 2021). However, these activities generate large volumes of wastewater rich in organic pollutants and nutrients that pose serious environmental threats if discharged untreated. The wastewater often contains suspended solids, blood, fish residues, phosphorus, nitrates, and chemical additives, which can lead to water pollution, oxygen depletion, and ecosystem disruption (Venugopal & Sasidharan, 2020). Moreover, intensive processing also elevates chemical oxygen demand (COD), suspended solids (SS), and other contaminants, thereby creating biohazards to humans and marine life (Thuan et al., 2024; Al-Dawery et al., 2023). Therefore, innovative and sustainable management of seafood processing effluent is essential to reduce pollution, protect ecosystems, and support long-term industry sustainability.

Seafood effluent typically contains high levels of organic matter such as fats, proteins, and blood from shellfish processing, which represent a major concern (Thuan et al., 2024). These pollutants are reflected in high Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD). Furthermore, wastewater often carries elevated suspended solids (SS), fat, oil, and grease (FOG), resulting from oil spillage, sauces, and brine removal during preservation and packing (Jamal et al., 2020). The wastewater is therefore characterized by high BOD and COD. For instance, in Atlantic Canada, seafood effluent concentrations were BOD5 (179–276 mg L⁻¹) and COD (458–1717 mg L⁻¹) (Tucker, 2000). Consequently, direct discharge depletes dissolved oxygen, causes eutrophication, and generates aquatic toxicity. In addition, high organic loads can overload treatment systems, producing excess sludge, odours, and reduced efficiency.

Unpleasant odour also arises from decomposing organic matter that releases volatile amines, diamines, ammonia, and hydrogen sulfide. The latter, generated from amino acid-rich fish degradation, has toxic and irritating effects, thereby endangering workers while creating nuisance concerns for nearby communities (Yan et al., 2024; Piccardo et al., 2022). At the same time, energy demand presents another challenge. Aerators and pumps, essential to maintain dissolved oxygen (DO) and water quality, account for 80% and 10% of energy use, respectively. Their continuous operation not only raises production costs but also increases environmental burdens from fossil-fuel electricity (Nguyen et al., 2024).

The industry also struggles with strict regulations, high costs, and limited technical capacity. Regulatory agencies impose limits on BOD, COD, and TSS discharges, thereby requiring advanced and costly technologies to comply (Venugopal & Sasidharan, 2020). However, inconsistent standards, inadequate infrastructure, and high monitoring costs further complicate compliance, often resulting in partially treated effluents that risk public and environmental health (Mokhtar et al., 2024). Moreover, nutrient-rich sludge disposal presents additional concerns. Because of its high nitrate and phosphate content, direct discharge contributes to eutrophication, harmful algal blooms, and water quality degradation when released into aquatic systems (Bhattacharya et al., 2022; Akinnawo, 2023).

Emerging technologies are therefore being developed to improve seafood wastewater treatment by promoting sustainability, energy recovery, and pollution reduction. For example, microalgae naturally assimilate excess nitrogen and phosphorus, converting them into biomass through photosynthesis. This biomass can then be harvested for animal feed, biofuel, and fertilizer (Hafiz et al., 2021; Mahari et al., 2024). Additionally, microalgae help fix carbon, increase dissolved oxygen levels, and assimilate both organic and inorganic compounds, thus providing a cost-effective option for treating shellfish farming wastewater (Wan Mahari et al., 2024). A study by Arbour et al. (2024) further reported that microalgae treatment efficiently removed nitrogen and phosphorus from shrimp wastewater, thereby outperforming conventional activated sludge.

In addition, biofloc systems employ beneficial microbes to detoxify pollutants such as ammonia, nitrites, heavy metals, and organic contaminants. Through bioleaching, microbial decomposition, bioflocculation, and biomass formation, this technology enhances nutrient recycling, reduces hazardous compounds, and improves seafood wastewater sustainability (Akange & Kasan, 2024). Likewise, Anaerobic Membrane Bioreactors (AnMBRs) combine anaerobic digestion with membrane filtration, generating pathogen-free, nutrient-rich effluent while occupying a smaller footprint. They also reduce sludge production and improve biogas generation, thereby enhancing energy efficiency in wastewater treatment. For example, Li et al. (2023) demonstrated AnMBRs’ application in Japan, showing significant improvements in effluent quality, reduced sludge, and higher energy recovery.

In conclusion, effective wastewater management in seafood processing is critical, as untreated effluent endangers aquatic ecosystems and human health. The key challenges include high organic pollution, odour, energy consumption, strict regulatory requirements, and sludge management. Therefore, addressing these issues demands innovative, sustainable, and cost-effective solutions. Emerging technologies such as microalgae-based systems, biofloc technology, and Anaerobic Membrane Bioreactors (AnMBRs) provide promising approaches for pollutant removal, resource recovery, and energy savings. By adopting these advanced systems, the seafood industry can consequently reduce its ecological footprint, protect marine environments, and achieve long-term sustainability through responsible wastewater management.

Prepared By:

Dr. Ezzat Mohamad Azman

Syafiqah Nazirah Jamali (214709)

Shaurah Hannani Shaharudin (214710)

Arisya Nabila Muhamad Razuhanafi (214969)

Chew Mei Qi (215024)

Dave Tan Ching Seng (215110)

Elany Wafiqah Mohd Hadi Sidney (215134)

Hoi Yuan Xin (215268)

Fang Yi Min (210314)

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Date of Input: 29/08/2025 | Updated: 29/08/2025 | nur_jasni