As the beach-going season comes around with the summer heat, it’s a good time for everyone to reflect on the importance of the sea. The ocean environment, which brings a variety of benefits to humankind, is facing a serious crisis.

One vivid manifestation is in a decline in fishery resources caused by overfishing. According to the United Nations Food and Agriculture Organization’s report “The State of World Fisheries and Aquaculture 2016,” production from the world’s marine fisheries fell to 80.9 million tons in 2013 from a peak of 86.4 million in 1996.

The share of fish stocks within biologically sustainable levels declined from 90 percent in 1974 to 68.6 percent in 2013. The percentage of stocks fished at biologically unsustainable levels increased from 10 percent in 1974 to 26 percent in 1989 and 31.4 percent in 2013.

The stock of Pacific bluefin tuna has now declined to a level at which extinction is feared, and Japan was severely criticized at an international meeting last year for its inadequacy in efforts to protect the species.

Illegal fishing by Japanese fishermen and large volumes of unreported catches have also surfaced. Among the seven principal tuna species, 41 percent of stocks were estimated at biologically unsustainable levels in 2013. About 70 percent of the principal market tuna species — albacore, bigeye, bluefin, skipjack and yellowfin — are from the Pacific.

In the waters near Japan’s coasts, stocks of fish species familiar to Japanese — such as red bream, Japanese common squids, tiger’s swellfish, sand lance, Okhotsk atka mackerel and Alaska pollack — are reportedly at low levels. If Japan wants to keep enjoying the benefits brought by the sea, the government should quickly introduce a strict fisheries resource management system to keep stocks at sustainable levels, backed by provisions for punishment for those who do not follow relevant rules, including the submission of correct catch reports to authorities.

The ocean environment is also threatened by industrial activity. Microplastics are polluting the sea — even at great depths and around the polar regions — a big issue that governments must tackle. In view of an estimate that 8 to 10 million tons of microplastics are finding their way into the sea every year, the United Nations Environment Program launched the #CleanSeas campaign in February to eliminate marine litter.

Materials used in facial cleaners and clothing, as well as excessive, wasteful reliance on single-use plastic are deemed mainly responsible for the growing presence of microplastics in the ocean. Microplastics are ingested by fish and sea birds. Japan needs to take effective measures to reduce the use of PET bottles, plastic bags and other plastic products.

Carbon dioxide released by the burning of fossil fuels also cause marine environmental problems.

The ecosystems that are surrounding coral reefs are under threat from the serious danger of coral bleaching — apparently due to rising seawater temperatures linked to climate change.

When the El Nino phenomenon occurred in 1997-1998, the resulting rise in seawater temperatures around the world killed 16 percent of all reef-building coral in 12 months.

In the summer of 2016, it was discovered that more than 90 percent of coral in the Sekisei lagoon lying between Ishigaki and Iriomote islands in Okinawa Prefecture was bleached and 70 percent of the coral was dead.

The absorption of large amounts of carbon dioxide causes acidification of seawater. It is feared that this will prevent corals, shellfish and plankton from forming shells, greatly affecting marine ecosystems.

It has also been reported that rising seawater temperatures are causing changes in the types and amounts of fish caught.

The preservation of the ocean environment and the resources it provides is one of the United Nations’ Sustainable Development Goals adopted in 2015.

It is regrettable that Japan — a country that benefits a great deal from the bounty of the seas — did not send a Cabinet minister-level official to the U.N. Ocean Conference held in New York in June to explore ways for conservation, sustainable use and development of marine resources under the goal.

Under the Basic Law on Ocean Policy, which took effect in 2007, the government has established a comprehensive ocean-policy headquarters and adopted a basic policy plan.

However, the headquarters remains a mixed bag of officials from different ministries and agencies, and the basic plan mainly focuses on the development and use of marine resources, giving little weight to preservation of the ocean environment.

The government should make protection of the ocean environment a main pillar of the plan, which is now being reviewed for an update, and create a central command post that can work out effective measures for preservation of the sea environment that will be able to override bureaucratic divisions.