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Posts tagged ‘Hawaiian islands’

7
May

Pacific Hurricane Formation

Pacific Hurricane Formation - Directory of KauaiIn the Pacific Ocean when an organized area of showers and thunderstorms intensifies, it becomes known as a tropical disturbance. This disturbance becomes an organized area of tropical low pressure that is called a tropical depression. A tropical depression’s winds are measured at 33 feet above the surface, and must be at or below 38 miles per hour when averaged out over one minute. These cyclonic winds go counter-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. Once average winds reach 39 mph then the cyclonic system becomes a tropical storm and receives a name. Tropical storm names are preselected and issued alphabetically for each storm, while tropical depressions are numbered.

A hurricane is a heat engine, powered by the latent heat energy released from condensation. That heat energy is derived from the ocean, and to develop it must be supplied with a constant supply of warm humid air for this process. When seawater evaporates from the surface, it takes heat with it. As the rising water vapor reaches clouds an incredible amount of heat is released, warming the air and driving the hurricane’s circulation. Surface air with enough energy to generate a hurricane only exists over oceans with a temperature greater than 80 degrees F and at least 600 feet deep. Ocean temperatures this high only occur in selected regions of our planet and during particular seasons.

On average, hurricanes that form in the North Pacific move in a west or northwestward path. In reality, the track taken by any individual storm is often very chaotic. Hurricanes can suddenly change both their speed and direction of travel.

30
Jan

Humpback Whale Count January 2012

Humpback Whale Count - Directory of KauaiVolunteers 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 950 participants tallied humpback whale sightings and documented the animals’ surface behavior during the survey. The sanctuary protects humpback whales and their habitat in Hawaiian waters where they migrate each winter to mate, calve, and nurse their young. Up to 12,000 humpback whales return to their Hawaiian birthplace every year between November to May after migrating from as far away as Alaska.

The following were the average numbers of whales sighted per 15-minute count period on each of the islands:
Kaua‘i – 8 whales
Hawai‘i Island – 3 whales
O‘ahu – 2 whales

On Kauai:
Kapa‘a Lookout – 8 average
Ninini Point Lighthouse – 14 highest 15-minute count
Crater Hill in Kilauea – 13 highest 15-minute count
Makahuena Point – 12 highest 15-minute count
Kilauea Lighthouse – 11 highest 15-minute count
Mahaulepu-Makawehi – 11 highest 15-minute count

Other marine wildlife seen during the Sanctuary Ocean Count included Hawaiian monk seals, sea turtles, spinner dolphins, and a variety of sea birds. Two more Sanctuary Ocean Counts are scheduled to take place on Saturday, February 25 and March 31. For more information on becoming a Sanctuary Ocean Count volunteer visit sanctuaryoceancount.org or call 1-888-55-WHALE ext. 253.

15
Dec

Ocean Health

Coral Reef - Directory of KauaiThe 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.

24
Oct

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.

9
Sep

Hawaiian Reef Fish and Achilles Tang

Hawaiian Reef Fish and Achilles Tang - Directory of KauaiAchilles 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.

2
Sep

Hawaiian Reef Fish and Surgeonfish

Hawaiian Reef Fish and Surgeonfish - Directory of KauaiSurgeonfish 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.

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