1. The large fish of many species (e.g., their breeding populations) are gone.
First inventories indicate that Pacific National Parks ' reefs are severely over fished and that very few large fish are left. This is a huge loss of spawning potential--consider, a single large female red snapper (24 inches) has the spawning potential of 212 smaller females (16 inches). Recovery of the large fish breeding capability needs nothing short of a wide reduction in the harvest of coral reef fish for at least a decade, and Marine Protected Areas (MPAs) must provide meaningful protection to fish stocks.
Another factor keeping fish stocks perpetual low is fishes' longevity (or lack of it). As more coral reef fishes have been aged, an unexpected pattern is emerging: the fish are far older than expected. They can live on the reef for decades; maximum ages of 20-30 years are common, even for small surgeonfish. Old views that coral reef fishes are high-turnover populations that can be fished hard because they grow fast and die young are wrong. Realization that coral reef fish can be old has significant management implications. Since mortality of their young is extremely high a fish has to live and spawn for decades in order to insure that at least a few of its juveniles successfully make it back to a reef and grow to maturity. Successful recruitment is a very rare event. And it becomes even rarer if the number of spawners has been reduced to a skeleton population through over fishing.
Consensus is that parks reefs are simply overfished. Even if current levels of fishing do not seem excessive, the reef areas are small and consequently easily fished out. Fish stocks may well have been depleted years ago--knowledgeable locals and elders recall seeing far more fish on the reefs 25 years ago.
All Pacific Islands parks' waters are subject to local subsistence fishing. Implicit in legislation establishing these parks is an ingrained view that Native and prehistoric peoples lived in harmony with the land, and they left no adverse effect upon their environments. Recent archeological studies refute that view, and widespread studies show that human occupants greatly modified the landscape and biota. The parks' current reef monitoring indicates that several large sanctuaries that exclude all fishing, continuously for decades, must be established within the park's MPAs for fish populations to recover.
2. Coral stress pulses (such as bleaching episodes) seem unnaturally frequent.
In the next few decades global warming, ocean acidification from skyrocketing CO2 emissions, and increasing local human threats are predicted to cause major stress to Pacific Park's coral reefs. Global warming will increase sea surface temperatures that can be lethal to corals. Increasing ocean acidification forecasts to make the seas unsuitable for corals within the next few decades. During the 1994 warming event in the south Pacific, extensive mortalities occurred among branching corals throughout American Samoa--especially on a shallow reef on Ofu Island. In 1999 and 2000, American Samoa narrowly missed being affected by a warm water mass that caused severe coral damage in the nearby islands of Fiji and (Western) Samoa. In 2002 and 2003, widespread coral bleaching occurred in American Samoa. Likely reef-building corals will be subjected to steadily increasing temperatures in future decades. Many of the parks' coral species are already near their thermal limits, thus warming events will cause unprecedented mass coral bleaching and mortality.
3. Periods of widespread siltation from adjacent shores are damaging some reefs.
On Guam, sediment runoff from local land abuse severely impacts coastal reefs. Population increases and land practice changes cause large increases in terrestrial runoff and decline in coral abundance, cover, and recruitment. Sediments can bury adult and juvenile corals, impair reproduction, and locally reduce coral recruitment rates. Even if sediment impacts are not always themselves lethal, sub-lethal affects impair coral ability to recover from acute shock from tropical cyclones or crown-of-thrown outbreaks. War in the Pacific National Historical Park watershed is protected by its inclusion within the National Park, but is still impacted by wildland fires, off-road vehicles, and development along its boundary--all of which contribute to increased soil erosion. Sediment plumes on the park reefs are a frequent sight following even modest rain.
4. Excessive nutrient enrichment from nearby uplands by both run-off and nutrient re-injection threatened alien algae blooms such as now occur in West Maui waters.
Park waters at Kaloko have constantly been threatened and violated by groundwater pollution from developments adjacent to the park. Guam waters are impacted by sewage outfalls.
5. Local subsistence over harvests are depleting the some key species' populations.
clam, sea turtles, lobster, some crabs, and lined surgeonfish populations (among
others) seem in deep decline, and larger individuals are becoming very rare or
absent. Contrary to prevailing mythology that local subsistence of marine resources
is benign, this over harvest is severely depleting several key species.
These new concerns prompted several initial responses from the Pacific parks and the National Park Service itself. View the parks' initial responses:
of Am Samoa
The National Coral Reef Initiative prompted immediate studies and inventories of the Park's marine environments. These raised several new concerns.