Shifting Baselines: what is the appropriate measurement of a healthy ocean?

When we examine a marine ecosystem or the population of a particular species and observe that "it's not what it once was," we are, in simple terms, observing a shifting baseline. The use of shifting baselines, or what has sometimes been called Shifting Baseline Syndrome (SBS), has become a common but controversial tool in evaluating fishery management, species population, and general ocean vitality. In fact, it has been used as the basis of study for a variety of scientific and societal conditions - from ocean conservation to Hollywood entertainment.

One of the challenges in using SBS is in determining what the fundamental baseline is - what is the baseline that represents a fully healthy, functioning marine ecosystem or species population? Is it what it was 10 years ago? A century? Or before the arrival of mankind? To determine such an ultimate starting point, scientists often have to take a variety of empirical and anecdotal data and work backwards. Sometimes this works, sometimes not.

As an example, one study in the late 1990's determined that the appropriate baseline population for green sea turtles in the Caribbean was 660 million, based on an extrapolation of the extent of a particular sea grass that figured prominently in the turtle's diet. Several years later, based on a reevaluation of the sea grass growth, that number was scaled back to 16 to 33 million - quite a reduction but still, given today's population of less than 200,000, what can we realistically expect as a conservation goal?

In other situations, SBS gets oversimplified in its application regarding policy. When research determined that over-fishing was the primary cause of a drop in Canadian cod fisheries, a moratorium was put in place in the early 90's. However, the cod population has failed to recover and the moratorium remains in place. What may have been missed is some unforeseen cascade effect, some other component to a healthy cod population that is missing or altered, perhaps triggered by the over-fishing, perhaps not.

Many scientists see value in using SBS but there are some who feel that it must be utilized in a more comprehensive fashion that also incorporates other theoretical approaches including resilience and social-ecological systems (SES) which introduce variables of human involvement or impact while trying to determine an appropriate future baseline.

In the end, it can be a vexing question: as we consider the health of marine species or ecosystems, what is the ideal goal that we can truly expect to strive for, regardless of how things were in the past? Can science accurately and reliably make that determination? Hopefully, it can but it will require a broad spectrum of scientific approaches to do so.

Click here for a proponent web site that explains shifting baselines.
Click here to read a scientific paper on SBS weaknesses and solutions.

Marine Life and Supply Side Economics: another reason for aquaculture

Both, the Shark Divers and Beqa Adventures blogs picked up on this post from the Southern Fried Science, a South Carolina marine biology grad student. It's a disturbing look at supply and demand economics regarding fisheries and it bolsters my attitudes regarding the importance of developing successful aquaculture. Here's a portion of the post:

"The basic premise is that many fisheries are completely supply limited. Even if we were to reduce 90% of the demand for certain fish, the remaining demand would still be great enough to consume 100% of the supply. If 100 people all love grouper, but only 10 grouper are being produced at any given time, then even if you convinced 90 people to never eat grouper, the other ten would still eat the 10 grouper being produced, and nothing would change. I was surprised that it’s taken me this long to start understanding what that means."

This also relates to shark products, particularly regarding the dollar value that increases with their continuing scarceness, even with reduced consumer demand. You can read the entire post here.

Marine Life & Climate Change: possible species invasion & extinction

Seaweb.org recently reported on a study published in the journal Fish and Fisheries which provided projections as to marine species invasion and extinction due to climate change, specifically the increasing ocean temperatures. The projections were based on climate change models including those of the Intergovernmental Panel on Climate Change. The results of William Cheung and his colleagues at Canada's University of British Columbia were also presented at a recent Chicago meeting of the American Association for the Advancement of Science.

What the report postulated was that with increasing ocean temperatures, many marine species would migrate towards the temperate to sub-polar regions. Extinctions would occur in tropical regions because of a species inability to migrate, while species in colder waters would be faced with both the same negative impact due to temperature increase plus the impact of invasive species (increased predation and competition). Semi-closed bodies of water (ex: the Mediterranean, the Red Sea), could experience high levels of extinction because of the species' inability to migrate due to geography.

The study pointed out the rate of extinction would be much lower than for terrestrial animals, the theory being that marine animals have a higher dispersal ability and can more easily migrate to suitable habitats. However, the impact by and to human populations can also enter into all of this in the form of decreased fishing in low income tropical economies - economies that depend on seafood on a very basic subsistence level, and in decreased fish populations in colder waters due to industrialized fishing for moderate to high income economies.

We often look to the Arctic and Antarctic for critical signs of climate change, indicators of profound changes. But we must realize it is a worldwide change which challenges all of nature, including man, on many different levels.

Marine Protected Areas: are they the hoped for success?

Marine Protected Areas (MPAs) and No Take Reserves (NTRs) have been instituted worldwide, from the South China Sea to the North Atlantic to the Mediterranean, as a method to not only preserve marine environments but also provide a means to ensure a reasonable population outside of the zone for commercial fishing. While common sense might dictate that these zones would logically improve the health of a marine environment, there are many challenges in empirically proving it.

While an MPA or an NTR may have a defined boundary, those limits have not been, shall we say, "communicated" to the marine life below the surface and so spatial density, or spillover as it is sometimes called, becomes a critical component. A healthy zone that generates populations of species that extend beyond its borders and provides a reasonable commercial yield, does not do so in a vacuum. There must be a proper flow of incoming influences including plankton, coral, and fish larval stages and other biosystem factors - all of which pay no attention to a zone's arbitrary boundaries.

While preliminary results appear positive, there is a considerable amount of challenging research taking place:

• Studying the impact of political/public use influences on the size (reduction) of a zone versus initial environmental recommendations (preliminary research indicates the negative effect is disproportionately larger than the amount of size reduction).
• Researchers are often challenged by a lack of extensive baseline studies of ecosystems prior to the zone for use in evaluating against post-zone studies.
• Much research needs to be done to document the relationship/effect of multiple MPAs or NTRs and how they interact with each other.

To date there have not been any major negative ecological effects attributed to MPAs and NTRs, but let's hope with more research over time, we will have the body of data to undeniably prove their effectiveness and how we can maximize or improve on that success for both environmental and commercial interests.

Scientists Confer: signs of progress in ocean conservation

The annual meeting of the American Association for the Advancement of Science recently concluded in Chicago and one of the results of the meeting was a recognition of progress in several areas of ocean conservation, particularly regarding fishery management in developing areas and coral reef health in protected or managed areas.

Several areas were cited for improved sealife populations due to effective fisheries management including Papua New Guinea, Indonesia, and Vanuatu. These regions were able to develop management programs that involved local communities in determining and managing protected areas. One of the challenges being faced is in "mid-development" countries - countries that have a growing commercial need for fishing but do not have the infrastructure in place to effectively manage their ocean resources. Poorer nations do not have the commercial means to severely impact their local sealife populations whereas well-developed countries have the required infrastructure in place to implement and enforce management policies. In between are the transitional mid-development countries that need both large bureaucratic and local community involvement - and there are places that have done that successfully.

"One of the things that we’re seeing that is giving me some signs of hope is that in many places throughout the Western Indian Ocean, there’s a real trend toward co-management. We’re seeing a very big devolution of power of managing of coastal resources from centralized governments toward communities," said Josh Cinner, social scientist from James Cook University. "There are some instances where you see examples of blending customary management and contemporary management. Where we do see this happening, we see great success—places like Vanuatu and the Solomon Islands, where there is considerably more fish inside of these community-managed areas."

During the annual meeting, it was also noted that healthy reef marine ecosystems have been shown to better withstand changes in their environment (temperature change, coral bleaching, etc.) - much like a healthy individual's ability to better ward off diseases due to good health that builds a strong immune system. The Pacific's Northern Line Islands were cited as an example and broader success is hoped for as these islands are within the larger U.S. National Marine Monument recently established.