Unless humans act now, seafood may disappear by 2048, concludes the lead author of a new study that paints a grim picture for ocean and human health.

According to the study, the loss of ocean biodiversity is accelerating, and 29 percent of the seafood species humans consume have already crashed. If the long-term trend continues, in 30 years there will be little or no seafood available for sustainable harvest.

The increasing pace of diversity loss thus imperils the "ecosystems services" that many human populations depend on for survival, the study says.

The research also found that biodiversity loss is tightly linked to declining water quality, harmful algal blooms, ocean dead zones, fish kills, and coastal flooding. (Related: 'Dead Zone' off Oregon Coast