title: Quantitative estimates of fish abundance from boat electrofishing

authors: Hicks, Brendan J.

subjects: biology

abstract: Multiple removals by boat electro-fishing were used to estimate fish populations in non-wadeable habitats in New Zealand lakes and rivers. Mean capture probability was 0.47±h0.10 (± 95% CI) from 35 population estimates made with 2-7 successive removals. The relationship between the population estimate from the Zippin method (Y)and the number of fish caught in the first removal (X) was significant (adjusted r2=0.84, P<0.001; Figure 2). The least-squares regression was Y = 1.55X 1.23. Mean density ± 95% confidence interval for 13 fishing occasions was 30±27 fish 100 m-
2. Mean biomass of fish for sites was 78±39 g m-2 (range 29 to 245 g m-2). Koi carp comprised the largest proportion of the fish biomass wherever they were present. The high biomasses of koi carp estimated in these results (mean 56±33 g m-2) suggest that they can reach problematic abundances in New Zealand. Bioniass of spawning koi carp can exceed 400 g m-2.

text: Quantitative estimates of fish abundance from boat electrofishing Multiple removals by boat electro-fishing were used to estimate fish populations in non-wadeable habitats in New Zealand lakes and rivers. Mean capture probability was 0.47±h0.10 (± 95% CI) from 35 population estimates made with 2-7 successive removals. The relationship between the population estimate from the Zippin method (Y)and the number of fish caught in the first removal (X) was significant (adjusted r2=0.84, P<0.001; Figure 2). The least-squares regression was Y = 1.55X 1.23. Mean density ± 95% confidence interval for 13 fishing occasions was 30±27 fish 100 m-
2. Mean biomass of fish for sites was 78±39 g m-2 (range 29 to 245 g m-2). Koi carp comprised the largest proportion of the fish biomass wherever they were present. The high biomasses of koi carp estimated in these results (mean 56±33 g m-2) suggest that they can reach problematic abundances in New Zealand. Bioniass of spawning koi carp can exceed 400 g m-2.

year: 2006

title: Why unavoidable moral wrongdoing is impossible

authors: Lane, Aaron

subjects: ethics

abstract: We can be faced with situations in which we act in accordance with the all-things-considered morally right course of action, and yet nevertheless experience an emotion of self-directed distress at the fact that we have so acted. Moreover, we have the intuition that this emotion is rational or appropriate. Literature is scattered with such examples, and they crop up not infrequently in life.

The fact that agents experience justified distress in such situations has been taken as evidence that unavoidable moral wrongdoing is possible. However, if this is the case, then the compelling intuition that an all-things-considered morally right action cannot be wrong must be false.

In this thesis, I offer a way of reconciling these two compelling intuitions that denies the possibility of unavoidable moral wrongdoing. I argue that existing attempts to dissolve this contradiction by arguing in favour of the possibility of unavoidable moral wrongdoing are unsatisfactory; and I contend that, by utilising Susan Wolf’s ideas on the “nameless virtue” (2001), developed in order to solve the problem of resultant moral luck, we can arrive at a more compelling method of dissolving the apparent contradiction. This solution is one that allows us to retain the intuition that a right act cannot also be wrong, while simultaneously allowing for the rationality of emotion of self-directed distress agents experience in situations of apparent unavoidable moral wrongdoing.

text: Why unavoidable moral wrongdoing is impossible We can be faced with situations in which we act in accordance with the all-things-considered morally right course of action, and yet nevertheless experience an emotion of self-directed distress at the fact that we have so acted. Moreover, we have the intuition that this emotion is rational or appropriate. Literature is scattered with such examples, and they crop up not infrequently in life.

The fact that agents experience justified distress in such situations has been taken as evidence that unavoidable moral wrongdoing is possible. However, if this is the case, then the compelling intuition that an all-things-considered morally right action cannot be wrong must be false.

In this thesis, I offer a way of reconciling these two compelling intuitions that denies the possibility of unavoidable moral wrongdoing. I argue that existing attempts to dissolve this contradiction by arguing in favour of the possibility of unavoidable moral wrongdoing are unsatisfactory; and I contend that, by utilising Susan Wolf’s ideas on the “nameless virtue” (2001), developed in order to solve the problem of resultant moral luck, we can arrive at a more compelling method of dissolving the apparent contradiction. This solution is one that allows us to retain the intuition that a right act cannot also be wrong, while simultaneously allowing for the rationality of emotion of self-directed distress agents experience in situations of apparent unavoidable moral wrongdoing.

year: 2025-10-17

title: Estimated catchment loads of nitrogen and phosphorus to the Rotorua Te Arawa Lakes

authors: McBride, Chris G.

abstract: The Rotorua Te Arawa Lakes are central to the identity of their region, of immense historical and cultural importance, and provide ecosystem services that underpin biodiversity, conservation and socioeconomic aspirations of the community. The diversity of water quality in the lakes reflects their catchments, which are diverse in topography, hydrogeology and intensity of land use, ranging from the largely undeveloped land around lakes Tikitapu and Okataina, to highly developed forestry and pastoral land around lakes Rerewhakaaitu, Rotorua and Okaro. Lake water quality is strongly linked to nutrients received by each lake from surface flows and groundwater springs. It therefore follows that management of lake water quality requires a good understanding of nutrient loads derived from the landscape, as does the assessment or prediction of the in-lake effects of catchment-based management initiatives aimed at improving lake water quality.

text: Estimated catchment loads of nitrogen and phosphorus to the Rotorua Te Arawa Lakes The Rotorua Te Arawa Lakes are central to the identity of their region, of immense historical and cultural importance, and provide ecosystem services that underpin biodiversity, conservation and socioeconomic aspirations of the community. The diversity of water quality in the lakes reflects their catchments, which are diverse in topography, hydrogeology and intensity of land use, ranging from the largely undeveloped land around lakes Tikitapu and Okataina, to highly developed forestry and pastoral land around lakes Rerewhakaaitu, Rotorua and Okaro. Lake water quality is strongly linked to nutrients received by each lake from surface flows and groundwater springs. It therefore follows that management of lake water quality requires a good understanding of nutrient loads derived from the landscape, as does the assessment or prediction of the in-lake effects of catchment-based management initiatives aimed at improving lake water quality.

year: 2021