ECO COMMENTARY

Perception of Ecological change varies from generation to generation

by The Green Hornett

Tuesday,  November 15, 2005

Many of us have sat with our grandfathers and listened to their tall tales – at least, that’s what they seemed at the time of telling. In the Cayman Islands the elders tell of the sea being full of turtles and of the crocodiles their fathers saw – the real caímans. 

The conch were so plentiful, they say, that all you had to do was wade into the sea and scoop them up. Soldier crabs roamed Grand Cayman, and a day barely passed when you didn’t see a blue iguana in the bush.

The same is true in other countries. I remember standing by a tidal marsh on the North American west coast, when an oldtimer standing next to me pointed up at flocks of migrating ducks which seemed, to me, to be quite plentiful. “I remember in the 1920s,” he told me, “the skies were black for days when the ducks migrated. 

When you wanted supper, you just pointed your gun at the sky and pulled the trigger. Supper just fell out of the sky.”

This comment was made at a time when biologists were worried that the number of ducks migrating through the salt marsh on the Pacific Flyway had dropped below 5 million. 

The old hunter told me that in the 1920s there were estimated to be well over 100 million ducks.

If we look at early photographs of turtling days we can see for ourselves just how plentiful the turtles were in these waters. The waters are dark with their swimming shapes. In our grandparents’ day it was quite normal to see hundreds of Nassau grouper, especially during spawning season. 
It also wasn’t unusual to see a 100-pound grouper – in fact, there were many fish of this size.

But you know something? Today’s generation will scoff and say that this is ridiculous. 

How can we know how many there were, or how big they were, when we never counted or weighed them in a systematic way?

No baseline data established

We never established any baseline data. Oh, we’re doing it now, with species counts carried out through the Department of Environment and non-profit groups like the Central Caribbean Marine Institute in Little Cayman. But it really is a bit too late.

The lack of baseline data means that our ability to fully comprehend the extent of environmental change over generations is hampered by “shifting baselines”, say the authors of a new paper, “Rapidly Shifting Environmental Baselines among Fishers of the Gulf of California”.

Authors Andrea Saenz-Arroyo and Callum Roberts, of York University in the UK, state that shifting environmental baselines are inter-generational changes in how people perceive the state of their natural environment. Each new generation unconsciously views as “natural” the environment they remember from their youth. 

People compare subsequent changes against this “baseline”, masking the true extent of environmental damage and often leading them to doubt the accuracy of historical anecdotes of past abundance.

While shifting baselines appear to affect all human societies, the evidence to date has been largely anecdotal – something certainly true of the Cayman Islands.

However, the study conducted by Saenz-Arroyo and Callum has tested the idea among three generations of Mexican fishermen.

Working in the Gulf of California, where fisheries have greatly intensified and fish stocks have declined steeply over the past 60 years, the scientists examined how quickly and to what extent environmental baselines have changed there.

“We asked fishermen to list sites and species that had once supported productive fisheries but that had become depleted. There was a dramatic shift in perception of what constitutes the natural state of the environment,” said Saenz-Arroyo. “Fishermen over 55 named five times as many depleted sites and five times as many species lost as fishermen under 30.”

The older men began fishing when the sea abounded with bull and hammerhead sharks, enormous groupers and snappers, Pacific green turtles, and large edible invertebrates such as rock oysters and conch. 

They testified how stocks of these animals had been depleted during the men’s working lives. But middle-aged fishers showed less appreciation of this past abundance, and most young fishers seemed unaware that these species had ever been common, the report states.

Sounds familiar, doesn’t it?

The Goliath grouper – gone

While older fishermen clearly recalled better environmental conditions than the young men, their experiences were very different from scenes witnessed by the first European visitors, the report continues. 

For example, few older fishers commented on the once valuable fishery for pearl oysters, which was abundant and extensive from the beginning of the seventeenth century until 1940, when the pearl banks collapsed. None of the fishermen’s testimonies matched the descriptions of seventeenth-century Spaniards such as Nicolas de Cardona, who wrote: “Along the sea coast of the interior region, over a distance of one hundred leagues all that one sees are heaps of pearl oysters.” 

Among today’s fishermen, few thought to mention the Goliath grouper, one of the world’s largest predators. This great fish was a favourite meal of seventeenth- and eighteenth-century buccaneers such as William Dampier. Now its very existence almost seems to have been forgotten.

“The speed with which environmental baselines can shift is troubling,” says Callum Roberts. “It wouldn’t be a great surprise for us to discover that people’s environmental baselines had changed in our suburbs and cities where people live at a distance from the wild. 

But our study shows they shift very rapidly among those whose occupations bring them into daily contact with nature.”

Many of the young fishermen interviewed came from fishing families. Despite their having older family members who could remember the sea being filled with huge fish, that knowledge does not seem to have been passed on.

Ecological degradation

The study shows that people fail to appreciate the scale of ecological degradation that happened before their lifetime. It helps explain why our expectations of nature are diminishing as time passes. “An understanding of past environmental conditions is essential for effective conservation today,” said Saenz-Arroyo. “Without such knowledge, environmental managers may set inappropriate targets based on depleted populations or degraded habitats, which perpetuates the cycle of loss.

“Our findings suggest a large educational hurdle must be overcome to reset people’s expectations for conservation, especially in developing countries where societies are dominated by young people.”

I believe that we in Cayman should follow the lead of the York University scientists and prepare a similar research paper on our own marine and land-based species. If the Department of Environment undertook such a study, both they and the people of this country would have a proper focus when it comes to conserving the populations of our own marine and terrestrial species.

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