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3 December, 2014 - 16:05

Responding to the paper on Hong Kong rocky shore ecology by Kennish et al. (1996).

Your research plan: Considerations!

The plan would include:

  1. A field visit at low tide to examine the broad patterns of plant and animal (algal and invertebrate) composition and distribution on the more sheltered A Man Wan coast and the more exposed Lung Lok Shui coast of Tung Ping Chau. Did the zonation pattern described by Kennish et al. (1996) for Cape d'Aguilar, Hong Kong Island appear at Tung Ping Chau?
  2. Measurement of the shore length at low tide.
  3. Drawings/photographs of the shoreline structure, e.g. wave-cut platform, dissected irregular rocky shorescape.
  4. Suitability of quadrat sizes: would 50 × 50 cm be adequate at Tung Ping Chau?
  5. Abundance of grapsid crab species Grapsus albolineatus, if not so abundant then do we have an alternative crab species on Tung Ping Chau?
  6. Should we scale down the number of crabs taken, e.g. would the removal of ~10 crabs/sampling visit be biologically bad and harm the ecology of Tung Ping Chau's rocky shore?
  7. Describe fully how algal fragments in crab guts were to be identified.
  8. Improve on the method/research plan used by Kennish et al. (1996) but completing a comparable study over two sets of seasons rather than 18 months and conduct the survey on both sides of Tung Ping Chau to fully address the possible influences of exposure vs shelter.
  9. Take into account that Tung Ping Chau is a marine park and, unlike, Cape d'Aguilar on Hong Kong Island which is, today, a marine reserve.
  10. The findings from such a Tung Ping Chau study may contribute to a move by the government to change the conservation status of Tung Ping Chau from marine park to marine reserve!

Points to improve upon: Critical evaluation for any future work

  1. Macroalgal survey used a 'stratified random sampling method' but the details of this were absent. How can sampling really be stratified and random at the same time?
  2. How, exactly, were the 15 quadrats (50 cm × 50 cm) randomly located? Were random numbers used?
  3. How many substrate types of each kind (rock, pool, crevice, etc.) were studied? Why were these details absent from the research paper?
  4. How was the percentage cover calculated? Details please!
  5. No mention of conservation of crab numbers, e.g. taking 10 crabs (5 males + 5 females) every month for 7 months may well influence crab population ecology. From a conservation view point, this crab removal action may have a negative impact on crab numbers and the ecology crabs influence. Why did Kennish et al. (1996) neglect to address this potential problem?
  6. It was not at all clear how the authors of Kennish et al. (1996) paper actually identified the algal fragments from crab gut contents!
  7. The details of dietary selectivity were not given. The scientific (not statistical) baisis of Vanderploeg and Scavia's (1979) selectivity coefficient were not given. The paper should have a stand alone quality and enable the reader/reviewer to fully appreciate the method, especially one as important as diet selection by the target organism, the crab!
  8. More work needed to be done on the taxonomy of the algal species: far too many species were not identified, e.g. Cladophora spp, Enteromorpha spp, Polysiphonia spp and some alga were only described as a growth from e.g. crustose corallines.

Finally, even if you thought of just 3–5 of these points, that would be evidence of good thinking. You were not expected to get all of these. The points given in this feedback can be looked upon as a brainstorming conducted session by two or three ecologists.