Areas of marine habitat (and terrestrial habitat) get declared as protected by agencies trying to fulfil roles in managing the conservation of nature. The effectiveness of such declarations is rarely investigated by adequate sampling. There are several reasons for this - starting with lack of coherent hypotheses about what should happen when an area is protected. So, "monitoring" is done, with no clear aims and little in the way of coherent sampling design to help provide the information that the managerial agency (and the general public) want and need. This is partially the fault of those who are in control and partially the fault of the scientists (or others) who do the work.
The issues in designing a valid and powerful programme of sampling to detect effects of "protection" are: a very clear framework of expectations about the outcomes of protection (in scientific terms, clear hypotheses); rational design of sampling at the relevant hierarchy of spatial scales; much improved design of sampling to detect trends and changes through time; a proper framework in which to determine whether any perceived changes are, in fact, a result of changed management; robust and reliable statistical analyses; proper and logical valid interpretation of analyses. Where so-called "indicators" are claimed to be useful, some proper understanding of how a scientist knows whether an indicator is, in fact, indicating anything useful (most are not).
