Humpback Whale Count January 2012
Volunteers collected data from 61 sites on the shores of O‘ahu, Kaua‘i, and Hawai‘i Island for the January Hawaiian Islands Humpback Whale National Marine Sanctuary Ocean Count. Over Read more
Ocean Health
The world’s oceans are under siege from pollution, overfishing, and other man-made problems all at once, and their health is declining much faster than originally thought. Troubles from global warming, dead zones from farm run-off, an increase in acidity from too much carbon dioxide, habitat destruction, melting sea ice, along with overfishing are worse when they combine with each other all at once.
At an international meeting of marine scientists was designed to consider the cumulative impact of multiple stressors on the ocean. The 27 participants from 18 organizations in 6 countries produced a grave assessment of current threats: that the world’s ocean is at high risk of entering a phase of extinction of marine species unprecedented in human history.
Case Study 1 In Brief: Most, if not all, of the five global mass extinctions in Earth’s history carry the fingerprints of the main symptoms of global carbon perturbations (global warming, ocean acidification and anoxia or lack of oxygen). It is these three factors which are present in the ocean today. In fact, the current carbon perturbation is unprecedented in the Earth’s history because of the high rate and speed of change. Acidification is occurring faster than in the past 55 million years, and with the added man-made stressors of overfishing and pollution, undermining ocean resilience.
Case Study 2 In Brief: What the multi-disciplinary approach of the IPSO workshop made clear for the first time was the multiple threats reefs are facing, that are now acting together to have a greater impact than if they were occurring on their own. This suggests that existing scientific projections of how coral reefs will respond to global warming have been highly conservative and must now be modified.
Case Study 3 In Brief: Continued releases and slow breakdown rates mean that legacy chemical pollution remains a major concern. However, concerns have been raised recently over a wide range of novel chemicals now being found in marine ecosystems or suspected to be harmful to marine life. Some of these chemicals have been located recently in the Canadian Arctic seas, and some are known to be endocrine disrupters or can damage immune systems. Marine litter and plastics are also of major concern, and there is evidence that certain plastics can transport other harmful chemicals in the marine environment.
Case Study 4 In Brief: Scientists agreed that overfishing is exerting an intolerable pressure on ecosystems already under attack by the effects of acidification and warming, and other largely man-made ocean problems. A recent study showed that 63% of the assessed fish stocks worldwide are over-exploited or depleted and over half of them require further reduction of fishing, in order to recover.
Some of the changes affecting the world’s seas – all of which have been warned about individually in the past – are happening faster than the worst case scenarios that were predicted just a few years ago.
Hawaiian Monk Seal Critical Habitat
Found only in the Hawaiian Islands, Hawaiian Monk Seals belong to one of the most ancient living groups of seals. Today their numbers hover at slightly over a thousand individuals, and continue to decline at a rate of 4% per year. Threats to their survival include fishing practices that allow seals to become trapped and drown in underwater nets, erosion of beaches where monk seals raise their young, exposure to diseases that occurs as a result of interaction with people, and climate change that is disrupting marine ecosystems and causing sea levels to rise and flood the seals’ breeding grounds.
Hawaiian Monk Seals (Monachus schauinslandi) are protected under the Endangered Species Act, but for years environmental groups argued the federal government wasn’t doing enough to halt and reverse their decline. In 2000, the Center for Biological Diversity and other groups filed a lawsuit to stop fishing activities that threatened to starve Hawaiian Monk Seals by reducing their food supply. This was the start of a series of legal fights that eventually resulted in a new critical habitat designation.
The 11,000 square miles now protected for Hawaiian Monk Seal recovery include shoreline and near-shore waters on all of the eight major Hawaiian Islands, as well as the tiny and mostly uninhabited islands in northwestern Hawaii. These northwestern islands are where the majority of Hawaiian Monk Seals currently live. However smaller monk seal populations have become established and are growing on the larger islands, making the critical habitat designations there particularly significant.
Hawaiian Monk Seals are wide ranging pinnipeds that require both marine and land habitats for reproduction, rearing, foraging and resting. New habitat protections, including all of the Hawaiian Islands, are essential to bring endangered Hawaiian monk seals back from the brink of extinction. Critical habitat compels US federal agencies to consider the survival of this Hawaiian seal before they permit shoreline development – protecting our beaches and reefs not only for monk seals, but also for Hawaii’s paddlers, fishers, surfers and all people of these islands.
Hawaiian Reef Fish and Achilles Tang
Achilles Tang, or Achilles Surgeonfish, are indigenous to the Hawaiian Islands. These Hawaiian reef fish are medium sized, growing up to 10 inches. The Achilles Tang (Acanthurus achilles) is mostly bluish black with bright highlights of white and orange around the margins of its fins and tail. The tail fin is mostly orange-red, with a thin black line and a wide white area at the back of the tail. When the fish matures, it develops an orange-red teardrop shaped mark near the base of the tail around the scalpel.
The Achilles Tang is a very territorial fish. They intimidate other fish with an aggressive burst of speed and a quick turn to display the sharp scalpel-like spine. They feed on algae, and prefer relatively shallow reef areas and turbulent waters found near wave action. Juveniles often shelter singly among finger coral in the deeper waters, and sometimes they swim in loose groups, but rarely in schools. The Hawaiian name, Paku‘iku‘i, refers to a method of scaring fish into nets by slapping and pounding water.
Hawaiian Reef Fish and Surgeonfish
Surgeonfish are some of the most abundant Hawaiian reef fish. Twenty-five species of Surgeonfish live in the Hawaiian Islands, and although they come in many different color variations, they all share the same basic structure. Their scientific family name, Acanthuridae, derives from the Greek word for “thorn.” They have hard spines at the base of their tail, one spine on each side of their body that lies flat in a groove until the fish is provoked. In times of danger, a surgeonfish will flip its tail and the spines pop out like a surgeons’ scalpel – thus the name surgeonfish. These spines are sometimes brightly colored.
Surgeonfish (some are called Tangs) are herbivores feeding mainly on algae and reside in the shallow waters of the coral reef. You will usually find them grazing alone or in small groups. They are similar to Parrotfish and Wrasses in that they primarily use their pectoral fins for propulsion.
Surgeonfish can grow to 22 inches, with the largest being the Yellowfin Surgeonfish. They average at 21 inches and eat almost any type of algae available. They are light tan in color with yellow pectoral fins and yellow markings around the eye.
The Whitespotted Surgeonfish can be found grazing on seaweed right where the surf is crashing. They are white and black with two large white stripes toward their head, and white spots covering the remaining two-thirds of their bodies. The white spots are part of their camouflage as they resemble bubbling water.
Orangeband Surgeonfish are also easily recognizable. They look like they are split in half with a white head and gray tail region. Their midsection starts out grey and ends in a black tail. They have a bright orange band in the white portion of their body placed just behind each eye.
Ocean Acidification Demonstration
Ocean acidification is the ongoing absorption of carbon dioxide from the atmosphere causing a decrease in the pH and increase in acidity of the Earth’s oceans. About half of the carbon dioxide in the atmosphere goes into the sea, and as the amount of carbon rises in the atmosphere there is a corresponding rise of carbon going into the ocean.
Human activities such as the combustion of fossil fuels and land use changes have led to a new flux of CO2 into the atmosphere. About 50% has been taken up by the oceans, with most of the rest remaining in the atmosphere. Between 1750 and 1990 the world’s oceans have seen an increase of around 30% acidity.
18th century 0%
1990s +18.9%
Present +28.8%
2050 +69.8%
2100 +126.5%
Natural seawater has an abundance of calcium carbonate minerals, which are building blocks for calcifying organisms to build their skeletons and shells. When carbon dioxide is absorbed by seawater, chemical reactions occur that reduce seawater pH, carbonate ion concentration, and saturation states of biologically important calcium carbonate minerals. Continued ocean acidification is causing many parts of the ocean to become undersaturated with these minerals, which is likely to affect the ability of some organisms to produce and maintain their shells. The degree of change to ocean chemistry, including ocean pH, will depend on the mitigation and emissions pathways society takes.
