Predator 2 Mega Drive

[Jacinto Man]

Asthe top predator of its day, Carcharocles megalodon devoured small baleen whales, seals, sea turtles, and large fishes in shallow seas around the globe, including here in the Chesapeake Bay region. It may have even swum where the Museum is now, back when much of Washington, D.C. was underwater. Though it went extinct 3.6 million years ago, this massive shark left a lasting mark (and lots of teeth!) in the fossil record.

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Both fire and predators have strong influences on the population dynamics and behaviour of animals, and the effects of predators may either be strengthened or weakened by fire. However, knowledge of how fire drives or mediates predator-prey interactions is fragmented and has not been synthesised. Here, we review and synthesise knowledge of how fire influences predator and prey behaviour and interactions. We develop a conceptual model based on predator-prey theory and empirical examples to address four key questions: (i) how and why do predators respond to fire; (ii) how and why does prey vulnerability change post-fire; (iii) what mechanisms do prey use to reduce predation risk post-fire; and (iv) what are the outcomes of predator-fire interactions for prey populations? We then discuss these findings in the context of wildlife conservation and ecosystem management before outlining priorities for future research. Fire-induced changes in vegetation structure, resource availability, and animal behaviour influence predator-prey encounter rates, the amount of time prey are vulnerable during an encounter, and the conditional probability of prey death given an encounter. How a predator responds to fire depends on fire characteristics (e.g. season, severity), their hunting behaviour (ambush or pursuit predator), movement behaviour, territoriality, and intra-guild dynamics. Prey species that rely on habitat structure for avoiding predation often experience increased predation rates and lower survival in recently burnt areas. By contrast, some prey species benefit from the opening up of habitat after fire because it makes it easier to detect predators and to modify their behaviour appropriately. Reduced prey body condition after fire can increase predation risk either through impaired ability to escape predators, or increased need to forage in risky areas due to being energetically stressed. To reduce risk of predation in the post-fire environment, prey may change their habitat use, increase sheltering behaviour, change their movement behaviour, or use camouflage through cryptic colouring and background matching. Field experiments and population viability modelling show instances where fire either amplifies or does not amplify the impacts of predators on prey populations, and vice versa. In some instances, intense and sustained post-fire predation may lead to local extinctions of prey populations. Human disruption of fire regimes is impacting faunal communities, with consequences for predator and prey behaviour and population dynamics. Key areas for future research include: capturing data continuously before, during and after fires; teasing out the relative importance of changes in visibility and shelter availability in different contexts; documenting changes in acoustic and olfactory cues for both predators and prey; addressing taxonomic and geographic biases in the literature; and predicting and testing how changes in fire-regime characteristics reshape predator-prey interactions. Understanding and managing the consequences for predator-prey communities will be critical for effective ecosystem management and species conservation in this era of global change.

This course will introduce students to key principles guiding the diversity of life in the oceans and driving marine ecosystem functioning. It will also introduce them to basic fisheries management concepts that will be expanded upon in subsquent modules. The overarching goal of this module is to bring students coming from varied backgrounds to a similar level of understanding of life in the oceans.

Key concepts covered:

- Marine biology principles

- Oceanographic principles

- Ecological drivers in the marine environment

- Marine ecosystem functions

- Introduction to fisheries biology and management

This module will survey fundamental aspects of the biology of different components of the fish community through lectures and practicals. At the individual level, the life cycles and life history strategies of fish will be summarised. Key aspects of population-level biology, including fish migration and population structure, will be covered. Case studies for a range of key Scottish species will also be covered. the relevance of fisheries biology to fisheries management will be highlighted throughout the course

This course will explore current understanding based on theoretical and empirical studies of processes operating in poulations of organisms. It will move from single isolated populations to single species populations arranged in space and linked by the movement of individuals, to consideration of trophic interactions, including predator prey, parasite host and plant herbivores as well as species embedded in more complex set of trophic interactions, including apparent competition. Simple discrete time models will be considered and used by the students to explore those interactions.

The module will run on three levels of spatial and temporal scales:

Week1: Individual fish growth and survival

- Students are introduced to a range of climate and lower trophic effects on individual fish survival and growth. Two types of computer models are used within the practical to illustrate the complexity of small scale predatory-prey interactions.

Week 2: Population dynamics

- The focus is on the assumptions and parameters which drive single species population models and what environmental information is left out of these traditional models. The practical will require students to simulate the dynamics of fish populations under a wide range of parameter values.

Week 3: Ecosystem modelling

- A contrast of biomass and process ecosystem models will be discussed and used in the practical. A staged debate will be held in which teams will back either single species ot ecosystem management practices.

Course Aims: Introduce core concepts of the link between organic matter input and marine benthic biodiversity and ecosystem function from estuarine shallow systems through to the deep sea.

Knowledge

By the end of the course students should be able to:

- understand that biodiversity regulates, as well as responds to, the environment

- understand, using benthic assemblages, the link between biodiversity and ecosystem processes such as bioturbation and nutrient generation.

Practical skills

By the end of the course the student should be able to:

- recognise principal benthic invertebrates from estuarine environments

- recognise principal deep sea benthic fishes

- analyse benthic time lapse imagery data

- be able to design and implement a field survey

Transferable skills

By the end of the course the student should be able to:

- engage during group discussion

- collect and analyse field derived data

- generation and testing of hypotheses

- understand functional group principles.

Content: This course will provide the students with hands-on experience of collecting benthic samples and data, in situ analysis of ecosystem processes and bringing these two arenas together. It also builds on the theoretical work they will have recived earlier in the course.

Criteria for species selection.

Diseases and Parasitology of fish and shellfish. Control and treatment. Health regulations. Epidemiology of disease.

Environmental implications of aquaculture.

Nutrition and feed technology.

Genetics and selective breeding.

Lectures will cover the theory and practice of assessing change in the size, status and distribution of seaboird abnd marine mammal populations. Our focus will be on UK monitoring and research programmes, but we will draw comparison with similar initiatives in the EU and North America. Practical sessions will include an introduction to the equipment, field and analytical techniques used in these programmes, and aim to build on key skills (e.g. GIS) developed earlier in the degree programme. Field trips will incorporate visits to key monitoring sites in the North East of Scotland, and discussion with organisations responsible for the monitoring, management and interpretation of these populations.

An important component of the courses will be the use of seminars, directed learning and group problem-solving to explore the factors that drive poulation change, and to assess the potential impacts of different types of human development on marine top predator populations. Lectures will also provide background to policy drivers and regulatory frameworks relevant to current issues in this area.

The first part of this unit deals with fishing gear technology and fish behaviour. It includes lectures on the various types of gear including trawls, gill nets and ghost fishing, as well as measurement and observation in gear experiments. Various behavioural concepts are covered including swimming and fish sensory systems with a further look at fish vision. A visit to FRS' Fish behaviour Unit (FBU) is included in this unit. The concept of selectivity is described in theoretical detail and is then followed by a description of the various selectivity techniques and a review of unaccounted mortality; a short practical on selectivity is given. A lecture on technical measures describes some of the main techniques used to control the fishery. A final lecture on applied behaviour considers how research can influence gear design and fishing practice.

The second part covers fishery independent (surveys) methods, with emphasis on the acoustic survey technique. This is another intensive week-long programme of lectures and practicals dealing with fishery independent (surveys) data. Lectures are given on each of the main survey methods: acoustic, trawl, larvae, egg and TV surveys. The general design concept, relating to all types of survey, is addressed in a lecture and illustrated through a practical as applied to acoustic surveys. Particular attention is then given to the more complex acoustic survey techniques. Lectures cover the physics of sound, acoustic instruments, the acoustic properties of fish and methods of biomass estimation. An acoustic survey data analysis lecture is followed by a practical which details the procedures from acoustic measurement to a global estimate of abundance. Finally, lectures are given covering survey statistics common to all methods, including one on geostatistics.

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