Revista Chilena de Historia Natural 83 (1): 143-157, 2010
Long-term monitoring of coastal ecosystems at Las Cruces, Chile: Defining baselines to build
ecological literacy in a world of change
Marine coastal habitats are being increasingly impacted by human activities. In addition,
there are dramatic climatic disruptions that could generate important and irreversible shifts in coastal ecosystems. Long-term
monitoring plays a fundamental and irreplaceable role to establish general baselines from which we can better address current and
future impacts and distinguish between natural and anthropogenic changes and fluctuations. Here we highlight how over 25 years of
monitoring the coastal marine ecosystem within the no-take marine protected area of Las Cruces has provided critical information to
understand ecological baselines and build the necessary ecological literacy for marine management and conservation. We argue that
this understanding can only be gained with simultaneous monitoring of reserves and human-impacted areas, and the development of
complementary experimental studies that test alternative hypothesis about driving processes and mechanisms. In this contribution we
selected four examples to illustrate long-term temporal fluctuations at all trophic levels including taxa from algae to sea birds. From
these examples we draw a few general lessons: a) there is co-occurrence of rapid- and slowly- unfolding ecological responses to the
exclusion of humans within the same rocky shore community. The sharp differences in the pace at which depleted populations recover
is at least partly related to differences in life history (dispersal capabilities) of the targeted species. b) Long-term monitoring of the
supply-side of marine communities is critical to evaluate the potential feedback effects of local changes in abundance into the arrival of
new individuals and to correctly evaluate environmental and human-induced perturbations. c) Unexpected changes in local population
dynamics can occur in “independent” and apparently non-interactive modules of the marine ecosystem, such as roosting sea birds
inside the reserve. In addition we discuss the way in which ecological data generated from long-term monitoring at marine reserves
was institutionalized in a national marine management policy. At the same time, we highlight the mismatch between the gained
scientific information and principles from these studies and the current concept of marine protected areas that is being implemented by
some government agencies in Chile. Information from long term monitoring programs has proved essential to understand how marine
environments respond to anthropogenic and/or natural disturbances, however funding these schemes, which generally have no short
term gains for funding agencies in both developing and developed countries, still remain a major challenge.
Key words:
community structure,
conservation, keystone species, marine reserves, policy
