Spatial distribution and seasonal variation in Undaria pinnatifida ...

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The low densities and infestation levels of Undaria at coastal sites may have been influenced by the timing of surveys,with nine sites having been surveyed in February when temperatures were warmest and Undaria is typically at its lowestdensities (see Section 4.2). However, to investigate the potential for seasonal variation to have influenced our results werevisited the Kirita site (mentioned above), where Undaria was reported in the November surveys, in February. All lifestages of Undaria were seen growing here both the site visits carried out on the 7/12/2011 and 3/2/2012 (Figures 5A and5B). Undaria remained prevalent on the mussel farms during February surveys, if only as large degraded sporophylls atsome sites.Figure 5: Undaria plantlets in coralline turf dominated habitat in the low intertidal zone (A) andmature Undaria sporophyte on the reef-sand border (~1m depth) (B). Kirita Bay, 3/2/12.AB12
4.1.2. Mussel farm surveyUndaria was recorded at all of the mussel farms surveyed on the western Coromandel Peninsula (Figure 6). No Undariawas seen on the two mussel farms surveyed at Kennedy Bay and one of the farms surveyed at Port Charles. Moredetailed maps are shown in Appendix 1. The highest infestation levels were recorded at all Wilson Bay farms (>500 plantsper 50m transect; Figure 7B), followed by three farms off Motukopake Island, Figure 7A, and one farm off WhanganuiIsland (>100 plants per 50m transect). Levels of Undaria infestation were defined as low to medium (1-100 plants per 50mtransect) on seventeen mussel farms, high (>100 plants per 50m transect) on eleven mussel farms and zero on threemussel farms. A trend of decreasing density of plants with increasing depth was observed (Figure 7A). Although depthprofiles were not taken at all sites, Undaria was generally seen to be most prevalent in the top two metres of water at allmussel farms. Plants were seen growing down to a depth of six metres at some sites (e.g. Motukopake and Wilson Bay).Figure 6: Western Coromandel Peninsula mussel farm survey locations: Orange paths indicate a mediumlevel of Undaria infestation and red represents sites where Undaria infestation levels were high. See Appendix 1for detailed maps and maps for Port Charles and Kennedy Bay.13
Page 1 and 2: Waikato Regional Council Technical
Page 3 and 4: Approved for release by:Peter Singl
Page 5 and 6: 11. Executive SummaryUndaria pinnat
Page 7 and 8: 2. IntroductionUndaria pinnatifida
Page 9 and 10: 3. Methods3.1. Spatial distribution
Page 11 and 12: For mapping purposes the Undaria ca
Page 13 and 14: 3.2.2. Westhaven monitoringWesthave
Page 15: Figure 4: Western Coromandel Penins
Page 19 and 20: Figure 8: Mussel length and Undaria
Page 21 and 22: Figure 10: Seawater nutrient data:
Page 23 and 24: 4.2.2 Temporal distribution and pop
Page 25 and 26: Figure 15: Average plant length at
Page 27 and 28: 5. Discussion5.1. Spatial distribut
Page 29 and 30: perennial macroalgae. Instead, plan
Page 31 and 32: and Johnson, 2003). Through this su
Page 33 and 34: Jessop, J., (2006). An investigatio
Page 35 and 36: 5Moturua Island6101112897Koputauaki
Page 37 and 38: 33Takawhare Bay, Windy Point/Puhe R
Page 39 and 40: 3/02/2012 Kereta South 36º 54’ 1
Page 41 and 42: 2/02/2012 Manaia7/12/20116/12/20116
Page 43 and 44: Appendix 4 - Size frequency distrib

Spatial distribution and seasonal variation in Undaria pinnatifida ...

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