Recreational impact versus public enjoyment
Recreational impact versus
In the above sections we have highlighted the value of rocky shores as
a public amenity for recreation and education, and the damage that visitors can cause.
Educational field trips may increase this impact through samples collection and localised
trampling. Easy public access lends conservation value to rocky shores. Ways should be
found to minimise disturbance without unduly restricting such access, especially in SACs.
Increasing public awareness may significantly reduce impacts of visitors, through
promotion of positive behaviour (Chan, 1970). Hawkins and Jones (1992) list guidelines to
minimise damage inflicted during field trips. A programme of public education could
involve signs explaining the conservation significance of the site or a visitor centre
(Fletcher, 1997), which may result in increased support for the SAC. It may also be
necessary to encourage the public to limit their use of the shore to designated areas.
Some site-specific research into the effects of visitors may be necessary.
Rocky shores are generally accessible, can be surveyed rapidly and are
well understood. Techniques involve low-cost equipment and give the potential for rapid
collection of quantitative or semi-quantitative data. Site visits are, however,
time-consuming and necessarily limited to the daytime low tide periods of just a few hours
each day. Consequently the choice of sites and the data collected need to be made
maximally effective. We believe that this can be best achieved by careful consideration of
the design of the survey in relation to the question asked, with a statistical
hypothesis-testing rationale as the main underpinning for the adopted scheme. Estimation
of abundance or cover estimates should be made for the main space-occupying (algae,
barnacles, mussels), abundant structuring organisms (grazers, predators), and other
species identified as important indicators of community type and environmental impacts. It
matters less that abundance or cover data is collected in a rapid semi-quantitative way
than that the sites and stations at which data are collected are chosen effectively.
Assignment of a shore community to a biotope should not necessarily be the final aim of
shore surveys, despite the attractiveness of the concept from a management viewpoint.
Long term studies following the Torrey Canyon oil spill demonstrate that rocky
shore communities can recover. The length of time this takes depends on the scale of the
disturbance. The extent of any recovery should be assessed by reference to baseline data
In many cases, shore communities will recover best without human
intervention and any post-impact management will often consist of monitoring this
recovery. Some exceptions in which additional measures may aid recovery are discussed
below. The Torrey Canyon incident illustrates that attempts to intervene can
backfire. The consequences of any measures should be carefully assessed before they are
Removal of litter
If the shore is badly affected by litter or debris, the only solution
is physical removal of the offending material. Mechanical methods should be avoided as
these may cause physical disturbance to the biological community. Removal by hand is
labour intensive but often effective. The Marine Conservation Society successfully
organises beach clean ups using a volunteer workforce.
Communities may never naturally recover from invasion by an introduced
species. The extent of the impact of a species on biodiversity will depend on several
factors. Measures to control the spread of particularly damaging species might be the only
way to conserve threatened communities. Many chemical and biological methods have been
used in attempts to control pest species. These control methods have had
varying degrees of success and often cause severe ecological consequences. The development
of safe and effective methods of control needs further research.
Some rocky shore species, such as dogwhelks, do not have a planktonic
dispersal phase and are slow to recolonize sites after disturbance. Recolonization may
occur only after adult individuals are transported to the shore by floating debris, for
example. Reintroductions may be attempted from nearby populations to speed up the natural
process. Some considerations need to be addressed before mass transplantation. Populations
of such species are often adapted to their home shore. Dogwhelks from an exposed shore
have low shells with large apertures which help them to withstand wave action but make
them vulnerable to predation by crabs which are more numerous on sheltered shores. The
ability of a population to survive in a particular area depends on the existing community
in that area, not least its prey species.