Habitat of the Month: Shallow Corals

Shallow corals have been called “the rainforests of the sea,” and with good reason—they support more species per unit area than any other marine habitat. They only cover a fraction of the ocean floor, but these complex tropical ecosystems rival the rainforests in terms of biodiversity.

Why is biodiversity so important? It means that shallow coral reefs are home to more than 1 million species. They also serve as habitat for many commercially important species targeted for fishing, like grouper, snapper, and lobster. The fish that grow and live on coral reefs are a significant food source for more than a billion people worldwide.

These shallow corals generally live in warm tropical areas where they receive a lot of sunlight, but corals can be found all over the world. Deep-sea corals live in cold oceanic waters, where they thrive on continental shelves, canyons, and seamounts, especially between 200 and 6,000 feet deep. These slow-growing corals can survive for thousands of years and are incredibly diverse, just like their shallow-water cousins.

What’s it Worth?

Shallow coral reefs provide many benefits, including:

• buffering shorelines from waves and storms that cause flooding and erosion
• supporting commercial and subsistence fisheries valued at more than $100 million annually
• containing important sources of new medicines being developed to treat cancer, arthritis, asthma, heart disease, viruses, and other diseases
• supporting a thriving recreation and tourism industry.

What’s the Problem?

These important ecosystems are in danger. Coral reefs are threatened by:

• pollution and marine debris
• sedimentation
• overfishing
• invasive species
• vessel groundings
• increasing tourism and recreation.

Reefs are also susceptible to the effects of climate change, such as rising water temperatures and ocean acidification.

What’s NOAA Doing?

NOAA works to conserve and restore coral ecosystems by addressing these threats. Recently, we proposed listing 66 coral species under the Endangered Species Act—seven species as endangered and 52 as threatened in the Pacific, and five as endangered and two as threatened in the Caribbean. Listing these species would allow provide NOAA more tools to protect and restore them, including developing recovering plans, designating critical habitat, and prohibiting “take” of the species.

In Hawaii, we removed more than 3 million tons of invasive algae from corals reefs in Maunalua Bay, which had originally covered 23 acres of corals. We also supported traditional farming techniques that reduced sediment flowing into Kaneohe Bay. We’ve removed more than 700 tons of marine debris from the Papahānaumokuākea Marine National Monument.

In Puerto Rico, we transferred 1,200 staghorn corals to nearby reefs—the largest single coral restocking effort ever undertaken in the Caribbean. The reefs had been impacted when an oil tanker grounded on a reef in 2008.

And in Florida, we grew threatened staghorn and elkhorn coral in nurseries to restore reefs damaged by bleaching, hurricanes, and disease. The initial goal was to grow 12,000 coral colonies, but the project raised more than 30,000 branching corals, which will help these coral populations recover.

Posted on 12/17/2012