Hawaiian Reef Fish and Bluestripe Butterflyfish
The Bluestripe Butterflyfish, who’s Hawaiian name is Kikakapu, is endemic to the Hawaiian Islands. The Bluestripe Butterflyfish (Chaetodon fremblii) is common among the shallow nearshore reefs to 200 feet from Oahu to Kure Atoll.
It grows up to six inches with bright blue bands running diagonally to obliquely along the fish’s yellow body, which becomes a darker yellow when the fish is alarmed. The fish also has a black spot above and behind the eye, and a black spot at the rear of the fish, extending onto the base of the tail and the dorsal fin.
They are often seen alone feeding on algae, tubeworm tentacles, and other invertebrates. Known as a relic species, the bluestripe butterflyfish has no obvious close relatives (which means that it has likely been in Hawaiian waters a very long time).
Hawaiian Wildlife and Spinner Dolphins 2
A hundred miles from Keahluhkekua Bay, the rugged, southern shore of the island of Lanai also provides sandy bays where the spinners can rest. By midday, the dolphins at Manele Bay are deep in sleep. Grouped together in tight formations, they sink to the sandy bottom, where they remain submerged for four to five minutes at a time.
This period of rest does not resemble sleep as we know it. The dolphins are not actually unconscious — as only parts of their brains are asleep at any one time. Most striking now is their silence.
Marten: There you can hear these click-whistles. And these whistles have been studied. . .
Dr. Ken Marten, director of research for earthtrust, studies the vocalizations of spinner dolphins. His office is alongside the bottlenose dolphin pool at sea life park, near honolulu. Marten analyzes the sound from videotapes of wild spinner dolphins.
Marten: …that’s one of the whistles there. . . . Now there’s a nice whistle. . . So what the scientist does it look at the course of the whistle through time. time is this way, on the x-axis. On the y-axis is frequency. And on the z-axis, in other words, intensity, the whiteness shows the intensity of the sound at that frequency.
Actually most of the sounds that we get from them are pulse sounds — “nyyea, nyyea” — things like that. And of course the pulse sounds go right up into the ultrasonic range. The pulse sounds are very difficult to study in that functionally they are a mixture of echolocation and communication. And who knows, maybe sometimes they serve both functions at once.
Echolocation sounds enable dolphins to track objects in dim or dark water… to in effect “see” much further than their eyes alone will allow. Their complex array of whistle sounds are the way that dolphins talk to one another. . . The spinners can even identify themselves with sounds they make while trailing bubbles from their blowholes — sounds called signature whistles.
This afternoon at lanai, the spinners have turned their sound systems off — allowing critically important areas of their brains to sleep. Now, without sound, they rely heavily on sight. And this is why clear water and white-sand bays are so important to them. During the period of rest, they must group tightly together, combining their eyes into a super-organ upon which they all rely.
For the next several hours, the dolphins maintain this semi-conscious patrol. . . rising and falling in tandem. . . drifting ghost-like through the shallows.
Poole:. . . animals at 8 o’clock. . .
On the other side of the equator, Dr. Michael Poole has been studying the spinner dolphins of french polynesia for more than ten years.
Poole: …vertical spin falling horizontal, 12 o’clock…
Like the hawaiian spinners, these tahitian dolphins also use volcanic islands as daytime resting sites. The french polynesian island of moorea is surrounded by a barrier reef. Inside the reef is a shallow, turquoise-blue lagoon — completely sheltered from the mid-ocean waves that pound the outer reef. Twelve passes through the reef allow the flow of water between the lagoon and the open sea. Spinner dolphins use these passes as doorways into the lagoon.
Poole: Activity at 1 o’clock. . . Forward slapping at 2 o’clock also, much closer. Forward slapping again, 2 o’clock. Forward slapping again. Side slap. Side Slap.
Michael Poole has extensively documented the dolphins’ use of the passes at Moorea. Although on any given day the spinners have a dozen passes through which to enter the lagoon, prevailing weather will generally reduce this number to only three or four.
Poole: This is one of the three bays that the dolphins use here on the east coast. It’s also one of the bays from which they’ve been displaced, or at least been displaced to certain regions of the bay. Poole has discovered that some of the critical resting sites for the spinners are now limited by a variety of manmade causes.
Poole: The animals have been moved from some areas into others because of the amount of boat traffic and jet ski traffic that we have here. There’s been an incredible increase in the past 5-7 years in the numbers of jet skis. Because they’re going so fast they often don’t see the dolphin school ahead of them and end up going right over it.
Today, ferries, speedboats and jet skis frequently drive the dolphins from the passes into the more shallow — and less favored — water further inside the bays. But these upper bays are also impacted — this time by human activities on the land. . .
Pineapples have become a major commodity in french polynesia. Yet many of these plantations have been poorly laid out. With each rain, tons of topsoil wash from the slopes and into the same white-sand bays where the dolphins come to rest.
Poole: Unfortunately due to the increased erosion due to agricultural practices, primarily pineapple plantations, we’re getting the white-sand bottoms of these areas covered with terrestrial sediments. The animals prefer to rest over white sand areas, so they’re now leaving areas, being forced out of areas because of this increased erosion.
Hawaiian Monk Seal Track
Hawaiian Monk Seals have been fitted with small transmitters glued on their back to help scientists understand their behavior in the main Hawaiian islands. For the seals’ health and safety, it must be hauled out in a sandy spot safe for restraint. The seal cannot be young, pregnant, nursing, molting, or otherwise already stressed.
Once attached, these devices reveal their movements, how deep they dive, when they haul out on land, and how far they roam. The seals are monitored remotely until the transmitters are shed when seals molt. One seal, known as RO18, often travels back and forth between Oahu, Niihau, and Kauai where he has been spending time with an adult female (RK13). This video tracks his movements.
Papahanaumokuakea Shipwrecks 1
The unique islands and atolls of the Northwestern Hawaiian Islands, which comprise Papahanaumokuakea Marine National Monument, possess a rich maritime history. Submerged maritime heritage resources, such as shipwrecks, sunken aircraft, and other archaeological sites are like windows into the past. There may be as many as 60 vessels known lost among the atolls and at least 67 naval aircraft sunk in the Northwestern Hawaiian Islands, but who knows how many more have yet to be discovered.
International Coastal Cleanup 2010
The Ocean Conservancy will host the International Coastal Cleanup on September 25, 2010. This annual event is the world’s largest volunteer effort to cleanup the marine environment and engages people from over 100 countries to:
- remove trash and debris from the world’s beaches and waterways
- identify the sources of debris
- change the behaviors that cause marine debris in the first place
The International Coastal Cleanup began in 1986 with one woman walking along the beach and becoming disgusted by the amount of trash she found. She arranged a beach cleanup, and her singular vision is now a worldwide movement. Last year, 500,000 volunteers from 108 countries covered 14,827 miles and picked up 7.4 million pounds of trash on a single day.
One of the things that makes this cleanup unique is that the volunteers record exactly what they find, giving us a snapshot of the litter and trash that is in our oceans and local waterways. Of the 10.2 million debris items collected worldwide, 60 percent of it was considered “disposable,” including over 512,517 cups, plates, forks, knives, and spoons, and 58,881 bottles of oil/lube.
Volunteers found 336 marine animals and birds entangled in marine debris. Ropes and old fishing gear can entangle wildlife and damage coral reefs. Sea turtles can mistake a plastic bag for a jellyfish, and birds and fish can easily mistake smaller debris for food – choking the animals, or blocking the digestive system.
Marine debris is one of the most widespread pollution problems we face, but with the help of the International Coastal Cleanup, momentum is building to reverse this trend. There is a growing understanding of the impact trash has on wildlife, and the need to stop marine debris at the source.
Green Sea Turtle Hatchlings
About two months after the female Green Sea Turtle covers her eggs with sand, the baby turtles are able to break through their shells by chipping away with a temporary hard protuberance on their beaks called an egg tooth. This is a unique tool that serves one purpose and then regresses.
Emerging from the nest is a group effort. Working together, the hatchings scrape away the roof of the nest until they reach about an inch away from the top surface. The hatchlings nearest to the surface stop digging if the sand feels hot (indicating daytime). They wait to resume digging until the sand feels cool and safer to emerge by avoiding the harsh rays of the sun and possible predators. Once out of the nest, the hatchlings find their way to the ocean, by heading towards the brightest horizon.
These first steps are the most dangerous time in their life. The young turtles are about 1.75 to 2.25 inches long and weigh 1 ounce, and various predators such as birds and crabs wait to pick them off, resulting in a large percentage of turtle hatchlings never making it to the ocean. Upon reaching the ocean, juvenile turtles spend from three to five years in the sea as carnivores before they settle into a more herbivorous, shallow-water lifestyle.
Hawaiian green sea turtles take around 25 years to reach sexual maturity. Their long period of maturation helps to explain why it takes sea turtles so many years to recover from a substantial population decline. Females begin returning to their natal beaches every 2 to 3 years to lay approximately three clutches of 100 to 150 eggs.
