Posted by Bill Dennison.
The Integration and Application Network has been working with various groups in Queensland, Australia to produce an environmental report card for the Great Barrier Reef, modeled in some ways after the Chesapeake Bay report card. Comparisons between the two large ecosystems can be made and these comparisons can provide insight into both Chesapeake Bay and the Great Barrier Reef.
As the title suggests, both Chesapeake Bay and the Great Barrier Reef are iconic in many ways. Their iconic status has to do with their respective sizes. Chesapeake Bay is the largest (or one of the largest estuaries in the world, depending on how estuary is defined). The Great Barrier Reef is inarguably the largest coral reef on the planet. Both are clearly visible from space, both have had many books and articles written about them. They are well studied scientifically, with many research institutions and universities studying them for over a hundred years each. They both attract thousands of tourists each year, who travel from great distances. They are in developed countries and are facing threats like land use change and climate change.
There are some important differences, and size is one of them. The Great Barrier Reef stretches for 2,000 kilometers (1,200 miles) from north to south, spanning from 10 to 25 degrees south latitude and the Great Barrier Reef covers an area of ~350,000 square kilometers (135,000 square miles). Chesapeake Bay, in contrast, is 360 kilometers (200 miles) from north to south, spanning from 37 to 40 degrees north latitude, and the Bay area is ~13,000 square kilometers (5,200 square miles). In spite of its immense size, the Great Barrier Reef is managed as one large marine park, with subregional Natural Resource Management areas. Chesapeake Bay has many parks within the Bay and the watershed, but it is managed by multiple states and entities, with the Chesapeake Bay Program acting as a coordinating body. The human population living in the watershed, or catchment, of Chesapeake Bay is ~17 million, but the Great Barrier Reef watershed only has ~1 million people. The key habitats of Chesapeake Bay are salt marshes, seagrass meadows, oyster reefs and soft bottoms, but the key habitats of the Great Barrier Reef are coral reefs, seagrass meadows, mangrove forests and hard bottoms. The Great Barrier Reef was discovered by Europeans relatively recently, in 1770 by Captain James Cook, but Chesapeake Bay was discovered by Captain John Smith in 1607. In short, the Great Barrier Reef, is 27 times bigger, 17 times less populated, tropical, rather than temperate, and more recently discovered.
In terms of scientific and management histories, both ecosystems have had a discovery phase, followed by a phase of identifying threats, followed by a phase of developing a modeling and monitoring program and are now engaged in a phase of accountability. This accountability phase is exemplified by the environmental report cards for both regions. Chesapeake Bay has an environmental report card for 15 subregions, using a combination of water quality and biotic parameters. The Great Barrier Reef report card has six subregions, using a combination of water quality, seagrass and coral parameters.
The past couple of months have demonstrated a major difference in precipitation between the two regions. The east coast of Australia is currently experiencing a severe La Niña cycle, as part of the El Niño/Southern Oscillation. This means that the prolonged drought that Queensland experienced over the past decade has been broken by significant rainfall events, leading to flooding and major plumes of freshwater laden with sediments, nutrients and toxicants spilling onto the Great Barrier Reef. This cycle of drought, punctuated by extreme events, is typical in Australia. Chesapeake Bay has much more consistent rainfall by comparison. However, the climate forecasts for the Chesapeake region are for more drought, punctuated by extreme events, so lessons from the Great Barrier Reef will be increasingly relevant.
The issue of diffuse or non-point sources of pollution are paramount in both ecosystems. In both cases, the federal government has allocated significant funds to incentivize farmers to conduct best practices, often managed through the state governments (Queensland in Australia; Pennsylvania, Maryland and Virginia in the U.S.). There is a similar reticence about sharing the data on implementation of agricultural best practices, but in Australia, the government has been more successful at getting self-reporting mechanisms in place and having this data shared.
On a scale of protection versus restoration, Chesapeake Bay management efforts are more focused on restoration, while the Great Barrier Reef efforts are more focused on protection. The iconic status of both regions means that significant attention and resources are devoted to each, and they serve as models for many other smaller programs. Now that reporting mechanisms have been established for both regions, it will be interesting to track the progress of the significant management efforts being made in both regions. In many ways, the future success of coastal management will hinge on the progress we make in these two iconic regions.