Monitoring the effect of cat removal on reproductive success in Red-billed Tropicbird colonies on Saba, 2013 - 2014: first season of results
Terpstra, M. ; Woude, E. van der; Wulf, K. ; Rijn, J. van; Debrot, A.O. - \ 2015
Den Helder : IMARES (Report / IMARES C103/15) - 32
animal welfare - wild animals - birds - cats - animal health - saba - feral cats - dierenwelzijn - wilde dieren - vogels - katten - diergezondheid - saba - verwilderde katten
One of the most deleterious invasive introduced predators worldwide is the domestic cat which has been found responsible for many island extinctions worldwide. Cats can live off both natural prey and garbage and can be a particularly serious threat to ground-nesting bird populations. Saba is an important location for the Red-billed Tropicbird, Phaethon aethereus and feral cats are thought to be the main reason for the low breeding success in the southern coastal colonies of this bird. To make proper decisions in invasive predator management, information is needed on the effects of cat removal on the tropicbird breeding success and the possible resulting increase in egg predation by rats in the case of any “mesopredator release effects”. In this study researchers collected the first season of data needed to assess the effect of cat removal on the breeding success of the tropicbird on Saba.
Scenarios for trans-boundary marine mammal management in the Wider Caribbean
Debrot, A.O. ; Bervoets, T. ; Rijn, J. van - \ 2014
Fast and Robust Method To Determine Phenoyl and Acetyl Esters of Polysaccharides by Quantitative 1H NMR
Neumüller, K.G. ; Carvalho de Souza, A. ; Rijn, J. van; Appeldoorn, M.M. ; Streekstra, H. ; Schols, H.A. ; Gruppen, H. - \ 2013
Journal of Agricultural and Food Chemistry 61 (2013)26. - ISSN 0021-8561 - p. 6282 - 6287.
acids - nmr - spectroscopy - extracts
The acetyl (AcE), feruloyl (FE), and p-coumaroyl (pCE) ester contents of different cereal and grass polysaccharides were determined by a quantitative 1H NMR-based method. The repeatability and the robustness of the method were demonstrated by analyzing different plant polysaccharide preparations. Good sensitivity and selectivity for AcE, FE, and pCE were observed. Moreover, an optimized and easy sample preparation allowed for simultaneous quantification of AcE, FE, and pCE. The method is suitable for high-throughput analysis, and it is a good alternative for currently used analytical procedures. A comparison of the method presented to a conventional HPLC-based method showed that the results obtained are in good agreement, whereas the combination of the optimized sample preparation and analysis by the 1H NMR-based methodology results in significantly reduced analysis time.
A baseline assessment of beach debris and tar contamination in Bonaire, Southeastern Caribbean
Debrot, A.O. ; Rijn, J. van; Bron, P.S. ; Leon, R. - \ 2013
Marine Pollution Bulletin 71 (2013)1-2. - ISSN 0025-326X - p. 325 - 329.
Data on beach debris and tar contamination is provided for 21 natural beach sites in Bonaire, Southeastern Caribbean. Transects amounting to a combined length of 991 m were sampled March–May 2011 and a total of 8960 debris items were collected. Highest debris and tar contamination were found on the beaches of the windward east-coast of the island where geometric mean debris concentrations (± approx. 70% confidence limits) were 115 ± 58 items m-1 and 3408 ± 1704 g m-1 of beach front. These levels are high compared to data collected almost 20 years earlier on the nearby island of Curaçao. Tar contamination levels averaged 223 g m-1 on windward beaches. Contamination levels for leeward west-coast beaches were generally two orders of magnitude less than windward beaches.