Meteorological influences on coastal sea levels west of Port Phillip and their engineering significance

This report presents the results of an analysis of three years of tide and meteorological data aimed at delineating the influences of atmospheric pressure, waves, onshore winds and longshore winds on coastal sea levels West of Port Phillip Bay, Victoria« The data was used to develop predictive and hindcasting techniques for meteorological tides on the Otway Coast, using statistical methods, an empirical method and a mathematical model. The nature and magnitude of contributions of the various components of the meteorological tide, and the general variability of monthly and seasonal variations were also studied. It was found that meteorological tides on the Otway Coast can account for significant sea level changes, with the main factors being wind and atmospheric pressure. The wind component of the meteorological tide was found to be approximately twice the pressure component, and longshore winds were found to be more significant than onshore winds for wind setup on the Otway Coast. The meteorological tide models developed enable estimates of wind setup and atmospheric pressure setup on the Otway Coast to be readily computed using data from synoptic charts. The wave setup component could not be separated from the meteorological tide and is included in the wind setup component. The results of the investigation are relevant to the design and maintenance of coastal engineering works, and point to the need for the establishment and operation of coastal management schemes on the Otway Coast.

Estimating survival and movements using both live and dead recoveries : a case study of oystercatchers confronted with habitat change

1. Animals facing partial habitat loss can try to survive in the remaining habitat or emigrate. Effects on survival and movements should be studied simultaneously since survival rates may be underestimated if emigrants are not considered, and since emigrants may experience reduced survival.

2. We analysed movements and survival of adult wintering oystercatcher Haematopus ostralegus in response to the 1986–1987 partial closure of the Oosterschelde in the Dutch Delta. This reduced by one-third the tidal area of this major European wintering area for waders.

3. We developed a novel variant of a multistate capture–recapture model allowing simultaneous estimation of survival and movement between sites using a mixture of data (live recaptures and dead recoveries). We used a two-step process, first estimating movements between sites followed by site-specific survival rates.

4. Most birds were faithful to their ringing site. Winter survival was negatively affected by winter severity and was lowest among birds changing wintering site (i.e. moving outside of the Oosterschelde).

5. During mild winters, survival rates were very high, and similar to before the closure in both changed and unchanged sectors of the Oosterschelde. However, the combined effect of habitat loss with severe winters decreased the survival of birds from changed sectors and induced emigration.

6. The coastal engineering project coincided with three severe winters and high food stock, making assessment of its effects difficult. However, the habitat loss seems to have had less impact on adult survival and movements than did winter severity.

7. Synthesis and applications. Human-induced habitat change may result in population decline through costly emigration or reduced survival or reproduction of individuals that stay. Long-term monitoring of marked individuals helps to understand how populations respond to environmental change, but site-specific survival and movement rates should be integrated in the same model in order to maximize the information yield. Our modelling approach facilitates this because it allows the inclusion of recoveries from outside the study area.

Implementing climate change policies consistent with integrated coastal zone management : a case study of Victoria, Australia

Whilst the proliferation of publications on climate change science is remarkable and makes the updating of responses to impacts of climate change on coastal environments daunting, the area of policy responses is even more confusing and complex. This is because policy responses do not need to consider the science of climate change alone but also have to weigh up the social and economic implications of the impact of climate change on coastal communities. In a federated nation such as Australia this has the added complication of three tiers of Government (Federal, State and local) having to interact in order to co-ordinate any policy responses. These complications should be aided by the internationally accepted concept of Integrated Coastal Zone Management (ICZM) which has been prevalent in Australian coastal planning and management for several decades. This paper uses the State of Victoria, Australia as a case study of how Governments are responding to these challenges through using the principles of ICZM. The paper will review recent inquires and investigations in Australia and canvas the policy responses to these reviews, concentrating on the State of Victoria. The paper analyses how consistent these evolving policy responses are with ICZM and suggests lessons for other jurisdictions arising from the Victorian experience.