Artificial Reefs: Solution or Problem
By Beth Alexander
They’ve been in use for thousands of years, with cultures as diverse as the ancient Persians, the Romans and the 17th-century Japanese creating artificial reefs. The earliest written record is from South Carolina in the 1830s, where logs were used to create an artificial reef for improved fishing. These antique ideas and creations have changed little over the years, with many of the primary principals remaining in use.
An artificial reef can be defined as a manmade structure that’s been built to promote marine life in areas with generally featureless bottoms, to control erosion, to block ship passages, or even to improve surfing conditions. Not all artificial reefs are purpose-built; some are created when a ship sinks accidentally. Whether they have been purposely or accidentally constructed, artificial reefs all provide hard surfaces where algae and invertebrates, such as barnacles and corals, can attach and form intricate structures, as well as provide plentiful food for fish.
Variables such as depth, water temperature, current, and the seabed composition determine whether an artificial reef will be successful or not, but generally they all follow a predicable growth formation: Ocean currents encounter vertical structures, which creates plankton-rich upwellings, which in turn provide reliable feeding spots for small fish like sardines and minnows. These draw in pelagic predators, such as tuna and sharks; next come creatures seeking protection, such as groupers and eels, then the opportunistic predators such as barracuda, and finally, over months and years, the reef develops more encrusting algae, sponges, hard and soft corals.
Proponents tout the many benefits of artificial reefs; they enhance resources in coastal waters, create biological reserves, attract tourism, allow the study of a reef’s development and productivity and can help nature to restore itself if the natural reef has been overfished or damaged by pollution or anchoring. One of these success stories is the deliberate sinking of the aircraft carrier USS Oriskany in Pensacola, Florida. It’s the largest purpose-sunk artificial reef in the world, and has been successful due to good management and planning. This wreck and others like it, which have been intentionally sunk, have proven to be great additions to the marine environment, encouraging coral growth and increased fish populations, as well as enabling divers to explore new and interesting environments apart from the natural reef.
But conservation solutions must be executed properly in order to be effective; good ideas are not enough if they’re plagued by human error. Introducing a manmade structure into a sensitively balanced marine ecosystem must be done with the utmost care. Pollution and toxic materials, such as asbestos from wrecks or oil from abandoned rigs, can seep from the structures into the marine habitat. An artificial reef can also lead to a high concentration of fish in one small area, creating heightened competition between species, and also, ironically, worsening overfishing in one specific area.
The prime example of a conservationist-minded idea going horribly awry is Osborne Reef off the coast of Fort Lauderdale, Florida. In the 1970s, an ambitious reef-expansion project was put into place, with the idea being that old tires would spread across a 36-acre site to form an artificial reef. Between 1 and 2 million old tires were deposited in the water, but many of them were never properly secured. Many broke free and subsequently drifted into and damaged the natural reef, only 69 feet away; storms have taken some tires as far away as North Carolina. In addition to destroying much of the natural reef, their mobility has prevented new organisms from taking hold on the tires. The Osborne Artificial Reef project has since been recognized as a great environmental disaster in Florida, and although limited clean up efforts have been undertaken, most of the tires remain in the water.
The introduction of foreign objects can cause a disruption to the natural ecological balance, but if it is done with environmental care and thoughtful planning, a successful artificial reef can provide habitat and recreation for years to come. When installed correctly, the benefits far outweigh the concerns, and it can only lead to better and more conservation when divers can see a new reef first hand.
The Philippines – a photographer’s dream
Posted by Andrew Jenkins
The Philippines is a photographer’s dream. The astounding landscape both topside and underwater glistens with colour and is calling out to be explored.
Start your adventure by passing through Manila, Philippines manic capital, perhaps stopping to take a ride on a rainbow coloured Jeepney – a kitsch vehicle that is one of the most popular forms of transport in this busy city. Once out of the city hub the variety that exudes within this tropical archipelago is hard to look past.
A perfect destination for scuba divers of all experience levels, the Philippines is in the heart of the coral triangle and is world renowned for nutrient rich currents and consequently some of the world’s most fascinating marine life.
Below are some fantastic diving locations to visit when traveling the Philippines:
- Cebu: placed neatly in the centre of the Visayan Archipelago, Cebu is a great place to learn to dive. With the second largest airport in the Philippines, it is easy to access and has a great range of dive sites. It is not uncommon to spot green turtles, giant frogfish and banded sea krait.
- Bohol: growing increasingly popular with backpackers visiting Panglao Island, Bohol is about an hour plane ride from Manila and usually offers a divers the opportunity of spotting huge schools of jacks. Colourful coral of hard and soft varieties make diving off Bohol a rainbow adventure you’re sure to love. The topside is also well known for the Chocolate Hills and the tiny Tarsier monkeys.
- Malapascua: this is an island that cannot be missed. Malapascua is one of the only places in the world where you’re almost guaranteed daily sightings of the rare and fascinating Thresher shark.
- Boracay: it is here that you’re likely to see grey reef sharks, manta rays and a plethora of tropical fish that inhabit the large assortment of corals. This is the most popular holiday destination.
- Subic Bay: this world renowned wreck diving destination is home to a plethora of historical stories that even the most advanced divers are sure to be impressed by.
- Tubbataha Reef: Although this reef is only accessible for three months of the year (March- June), this World Heritage Marine Park is well worth the visit. Accessing this area by liveaboard is the only option but the pristine corals which are populated with intriguing macro life, turtles and a wealth of tropical fish make this location a real gem.
- Puerto Galera: Ideal for those interested in drift diving, these current rich waters are imbued with snapper, barracudas and smaller tropical fish. There is the opportunity to do a night dive and potentially see the gorgeous Mandarin fish. Puerto Galera is based at the Verde Strait, which has the some of the world’s greatest biodiversity.
- Dumaguete: here you can experience the magnificent beach dives that macro enthusiasts are sure to love. In the deeper waters, the strong current often brings large schools of big-eye trevally and Spanish mackerel.
- El Nido and Coron in Palawan: There is no denying that Palawan is a picturesque tropical paradise. The topside is decorated with the most magnificent lime stone cliffs, and below the crystal clear horizon is the awe-inspiring wrecks in Coron and a range of tropic fish off El Nido.
Question: What time of year can I dive the Philippines?
Answer: In terms of water temperature and visibility, any time of year is just great - the water temperature is around 28C. What you do need to be aware of is typhoon season which typically extends from August to December. The typhoon belt starts at 10 degree latitude which is more or less north of Cebu City. Thus choosing dive sites below Cebu City especially from August to December, you should be reasonably sure of avoiding lost diving time through typhoons.
Question: What type of wetsuit is appropriate.
Answer: A 3mm wetsuit should keep you warm enough. Some "thick skinned" divers are even comfortable with a 1mm skin. Shorties are fine but long westuits can be useful when there are jelly fish around. We often come across really small jellyfish which are hard to spot but still give a sting.
Question: What can I expect to see?
Answer: In general at good dive sites, you can expect to see a diveristy of hard and soft coral, a lot of macro critters, and a good mix of reef fish. Genrally fish polpulations and fish sizes are on the low size due to over fishing. Check out the dive books and dive forums to find out the special attarctions at each site. For example the major special attraction at Moalboal, Cebu are the "clouds" of sardines to be found at Pescador Island. These shoals of fish attract many predators such as jacks, barracuda, tuna and thresher sharks. This really is a site not to be missed.