When diving, I always scan the ocean floor for sea stars, whose intricate body surfaces are often reminiscent of the gaudiest, most psychedelic 1960s wallpapers. If you look closely at sea stars’ skin, you might spot the tiny crabs and shrimp that make their homes there. These crustaceans spend their whole postlarval lives as guests on the body surfaces of larger animals, such as sea stars and sea slugs. It would be like a human living on top of a giant elephant. Like so much about minuscule marine animals’ behavior, the commensal relationships that tiny crustaceans participate in are not wel ..read more

Sponges. Is there anything they can’t do? For millennia, humans have used dried natural sponges to clean up, to paint, and as vessels to consume fluids like water or honey; we’ve even used them as contraceptive devices. Whether synthetic or natural, sponges are great at ensnaring tiny particles in their many pores. And as scientists around the world are beginning to show, sponges’ cavity-filled forms mean they could provide a solution to one of our era’s biggest scourges: microplastic pollution. In August, researchers in China published a study describing their development of a synthetic spong ..read more

Peter Kyne sits down at his desk to write a eulogy for a fish he’s never met. It’s summer 2019. No scientist has seen signs of the critically endangered Rhynchobatus cooki, or clown wedgefish, since a dead one turned up at a fish market in 1996. Kyne, a conservation biologist at Charles Darwin University in Australia who studies wedgefish, has worked only with preserved specimens of the spotted sea creature. “This thing’s dust,” Kyne thinks, feeling defeated as he writes the somber news in a draft assessment of the global conservation status of wedgefish species for the International Union for ..read more

Satyam Tripathi, a 27-year-old seafarer from Uttar Pradesh, India, leans against the railing of the MT Pablo, the oil tanker that has been his home for the past several months. Though the days at sea often blur together, today stands out as vividly as the South China Sea below. Today is his birthday. Moments later, his mother calls on WhatsApp. How are you? she asks, forgetting her birthday wishes for her usual motherly enquires: are you as happy at sea as I know you to be on land? Tripathi had acclimatized quickly to life in the merchant navy. The oil tanker is a surprisingly social place, an ..read more

Wild pigs roam the globe. Originally from Eurasia and North Africa, they’re now one of the most invasive species worldwide, trotting from the pine forests of North America to the wetlands of Oceania. Despite their world domination, we know little about how they’re taking over or the impact they have on ecosystems. A multi-institution collaborative study conducted by researchers from Singapore, Australia, and the United States tracked the movement of wild pigs in Singapore, in particular the speed and geographical distribution of their dispersal. Integrating interviews with local wildlife resea ..read more

On the northern coast of Java, Indonesia, climate change and anthropological stressors are resulting in coastal erosion and sea level rise, severely affecting coastal communities. In Demak Regency, the coastline has eroded especially quickly in the past years. Mangroves that protected the shore have been cut down and replaced by aquaculture ponds. At the same time, groundwater extraction for domestic and industrial uses has caused the soil to subside. This combination leaves the coastline and community exposed to the daily tides and extreme weather events that are occurring more frequently du ..read more

A harlequin shrimp’s jaunty coloring belies its killing tendencies. The shallow-water dweller, roughly the size of a plum, feeds exclusively on sea stars. To prepare for a meal, the shrimp flips its prey over and then breaks into it with special front mandibles. I have observed harlequin shrimp removing whole arms off their victims. Yet, I have never seen a harlequin shrimp with a dead sea star. I suspect the shrimp dissect a few limbs and then release their prey. Perhaps their intention is to ensure a continuous food supply, as sea stars are generally able to regenerate lost arms. I found th ..read more

The strong afternoon sun bears down on the coastal town of Can Thanh in southern Vietnam, but inside Lăng Ông Thủy Tướng—a single-story, pale-yellow building on the town’s shoreline—it is cool. Diffused sunlight illuminates the main hall, and the air is laden with the woody aroma of burning incense. A lone man, most likely a fisherman, enters the hall, walks toward a 20-meter baleen whale skeleton displayed in a glass case, and folds his hands in deep reverence. Lăng Ông Thủy Tướng—the temple to the god of the sea—is one of 1,000 or more such shrines on Vietnam’s 3,260-kilometer coastline. At ..read more

For the first time, scientists have confirmed a live sighting of an elusive species: the Sato’s beaked whale. For decades, Japanese whalers have been aware of a black whale that resembles the larger Baird’s beaked whale, a species that they hunt in the Pacific Ocean. But, until recently, the smaller whale was unknown to scientists. In 2019, a Japan-based research team described the species scientifically after analyzing the DNA and physical features of deceased specimens. Still, scientists had yet to see one alive and take the necessary genetic sample to confirm it. Then, during the summer of ..read more

Spotting a bundle of unhatched clownfish is pretty special. Adult clownfish spawn every 10 to 14 days and lay as many as 1,500 eggs on rocks or other hard surfaces. As the larvae develop, they seem to peer, wide-eyed, out of their egg sacs. The transparent, five-millimeter-long babies emerge after about 10 days. I’ve yet to watch one hatch, as the actual timing is hard to predict and only happens in darkness. I found this cluster of juvenile clownfish, covering a patch of rock about as wide as a side plate, during a dive near Anilao, Philippines. So much about the clownfish fascinates me: eac ..read more