Spatial distribution and seasonal variation in Undaria pinnatifida ...

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4.1.4. Other Invasive SpeciesOther invasive species recorded during coastal surveys are shown in Appendix 2. The invasive tunicate Styela Clava wasrecorded at ten of the twenty six coastal sites surveyed. The invasive alga Codium fragile ssp. tomentosoides wasrecorded at two coastal sites and the Asian paddle crab Charybdis japonica was also seen two coastal sites. Results forinvasive species recorded on mussel farms are shown in Appendix 3A. All the mussel farms surveyed had Styela Clavagrowing on the lines and/or infrastructure. Twenty eight of the thirty one mussel farms surveyed had Codium fragile ssp.tomentosoides present. Styela Clava and Codium fragile ssp. tomentosoides were abundant on the mooring lines atTakawhare Bay. Styela Clava, Codium fragile ssp. tomentosoides and Charybdis japonica were recorded at the Waikawauboat ramp site and at Kirita Bay.4.1.5. Environmental DataSite environmental information for the spatial survey is shown in Appendix 3B. During this survey average salinityrecorded at mussel farm sites was 34.7 ppt with a range of only two parts per thousand recorded across all sites,maximum 35.5 ppt, and minimum 33.5 ppt. The average temperature recorded over the survey was 18.7ºC with aminimum of 16ºC and a maximum of 20.6ºC. Temperatures were measured at different times of day and in varyingweather conditions so cannot be directly compared between sites. Secchi depths are shown (from northern (left), tosouthern (right) locations) in Figure 9. Sites had an average secchi depth of 5.9m across all mussel farm sites with amaximum of 8.5 recorded at Wilson Bay and a minimum of 4m at Koputauaki Bay.Figure 9: Secchi depths: Spatial survey locationsSeawater nutrient data is shown in Figure 10. Very high ammonia readings seen at Port Charles, Motorua Island,Koputauaki Bay, Motukopaki Island, Motukakarikitahi Island and Whanganui Island were all samples taken in November.Differences in ammonia levels at the same site can be seen for Port Charles, Motukopaki East and Kirita Bay as they wereeach visited in November, visit 1 and February, visit 2. Nitrite and nitrate were relatively variable among sites, with thehighest concentrations recorded in Port Charles and Manaia Harbour, as well as at one site at Motukopake Island.Nitrogen concentrations were typically low at the Wilson Bay farm sites. Phosphate occurred at relatively constantconcentrations among sites and times. For details on sampling dates and sites see Appendix 3B.16
Figure 10: Seawater nutrient data: Spatial survey locations4.2. Seasonal monitoring of Undaria populations4.2.1 Environmental variation at monitoring sitesOverall, seawater nutrient concentrations were similar between the Coromandel and Westhaven monitoring sites (Figure11). Nitrate and nitrite tend to be highest in winter, whereas ammonia is generally higher but highly variable over thesummer months (from November onwards). Phosphate is relatively stable through time and similar between sites.Figure 11: Seawater nutrient data at Undaria monitoring sites: Westhaven Marina (A) and Coromandel (B).A17
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 and 16: Figure 4: Western Coromandel Penins
Page 17 and 18: 4.1.2. Mussel farm surveyUndaria wa
Page 19: Figure 8: Mussel length and Undaria
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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