Fish and People

Pre-colonial Pacific Island societies by and large existed at human population densities that were far below the carrying capacity of their coastal fisheries and pressure from commercial fishing was non-existent. As a consequence island communities did not ‘encounter the limits’ of their coastal subsistence fisheries. People went about their daily lives harvesting from the sea and blissfully unaware that fish and marine invertebrate populations could be overfished to the point collapse. 

Now that human populations are growing almost exponentially and export markets for some fisheries are intensifying, there is an urgent need for the effective communication of a scientific understanding of the limits to fisheries and the life cycles of marine organisms overall. Fish and People is a 50 minute production divided into 5 educational modules explaining the ‘stock-recruitment relationship’ in an easily accessible manner and with a cleverly crafted portfolio of explanatory graphics and natural history vision. It deals with species that are of economic and ecological importance and thus immediately familiar to a Pacific (and broader) audience. The modules are tailored for middle and upper high school students and wider communities and are accompanied by a comprehensive teacher’s guide.

By empowering a critical mass of young adults with a clear understanding of how overfishing destroys fisheries and food security, they will potentially innovate their own, ‘bottom-up’ fisheries management strategies as they assume positions of influence within the community, as well as gaining a greater understanding of the need for compliance with ‘top-down’ management approaches such as size limits, gear restrictions, trade agreements and quotas. 

Fish and People has been scripted by marine biologists Simon Foale and Russell Kelley, and produced by The Eco Media Production Group. 

 

The School Program

Module 1: Are Fish Populations Declining?

In this introduction module, elders, fishers and scientists describe in various ways how fisheries are declining everywhere. Fish and other economically important marine species are declining in both abundance and size, and these declines have been dramatic within living memory of many people. These declines are primarily driven by increases in human populations, the expansion of markets, and improvements in fishing technology.

The concept of ‘fishery production’ is explained, along with key idea that recruitment is related to stock size. This will be examined in more detail in later modules. We also illustrate, using animations, some of the main techniques used by scientists to measure changes in abundance and size of fish and other species, including catch-per-unit-effort, and transect surveys. 

  Download Module 1  (371 Mb)

  Download Lesson Plan and Teacher's Guide  for all modules (23 Mb)

Module 2: The Life Cycle

An understanding of the life-cycle of marine fish and invertebrates is critical to understanding the connection between over-harvesting and the decline of fished populations, in extreme cases to the point of collapse. Most marine fish and invertebrates have an invisible (to the naked eye) larval stage that disperses in the plankton, and is capable of settling in a new location (recruiting) and becoming a juvenile.

The distance that larvae of different species disperse is determined by their biology and behaviour, and the prevailing currents. Some species have larvae that are capable of dispersing much greater distances than others. Most fish and marine invertebrates reproduce by spawning – the simultaneous release of gametes (sperm and eggs) into the water. Sperm then fertilise eggs and the fertilised egg becomes a zygote, which then undergoes cell division to form an embryo, which then develops into a larva. The dispersal, and eventual settlement of the larva into a new habitat, and its transformation into a juvenile, completes the life cycle. 

  Download Module 2 (424Mb)

Module 3: What Controls the Rate of Increase of Fish Populations?

This module explains why populations of some species can increase more rapidly than others. It deals primarily with aspects of the biology and natural history of species, and how these affect their population dynamics in the context of fishing. Growth rate, age at maturity, and life span vary greatly among different species of marine animals. Sardines and squid are well known to be fast growing and short-lived, while turtles, dugongs and some large species of fish are slow growing and long-lived. Following depletion by fishing, the populations of short-lived and fast growing species can rebuild themselves much faster than populations of long-lived, slow growing species. Populations of the short-lived and fast- growing species are regarded as being more resilient to overfishing. They are also regarded as having higher productivity.

Some species are also more fecund, or capable of producing many more eggs than others, and this can also have a strong effect on the speed with which populations grow. Age at maturity determines how quickly a species can start reproducing. All species must grow for a time before they can accumulate the energy reserves to allocate to reproduction. Populations of species that are able to reproduce early and often tend to have high rates of increase.

 Download Module 3

Module 4: Scales of Dispersal and Scales of Management

This module builds on some of the concepts introduced in Module 2, and looks in greater detail at the process of larval dispersal and the biological attributes of larvae that affect how far they travel before settling and transforming into juveniles. The length of time larvae must remain drifting in the plankton before they are capable of settling determines how far they are likely to disperse from where they were spawned.

Larvae that are unable to feed while in the plankton must settle as soon as they have exhausted the energy supply they were born with (the yolk of their egg). Larvae that are able to feed (on microscopic organisms) while in the plankton are usually capable of dispersing greater distances. Larvae can often detect the smell and the sound of their preferred habitat and often swim towards it.

Knowledge of larval dispersal patterns is crucial for understanding how populations are replenished at different spatial scales (i.e. large or small distances from each other). These connectivity patterns depend on larval biology and behaviour, and ocean currents, as well as the numbers and densities of reproducing adults in a population. A breeding population in one location can supply larvae to replace adults removed by fishing in another location, but this depends on distance, larval biology and currents.

 Download Module 4

Module 5: Human Populations and Fishery Management

This module is primarily concerned with how we think about and measure fishing pressure. Fishing pressure is a product of 1) human population size and density, 2) markets (domestic and export), and 3) technology (fishing gear). These are outlined in more detail below.

Human population size and density: large populations place more pressure on fisheries than small populations. Human populations everywhere are growing so fast that scientists worry that it is only a matter of two or three decades before there will not be enough fish to feed everyone, even if fisheries are well managed.

Markets: because people in regional towns, cities, and in other countries want to eat fish, and have money to pay for it, markets mean that local population pressure is not the only thing to consider when we think about fishing pressure.

Technology: 100 years ago the tools for catching fish were significantly less effective than they are now. Modern fishing tools include high quality diving masks, flippers, air compressors, Global Positioning System (GPS) devices and a host of other high-tech systems that mean that fish have a much lower chance of evading capture.

All of this adds up to a much greater need for an awareness of the vulnerability of fish populations, and the increasingly urgent need for careful management of fishing pressure, so that we can all enjoy fish into the future. 

 Download Module 5

Image Gallery

 

TelekomTelekom Television Limited (TTL) are an innovative, progressive corporate entity providing of state-of- the-art television, telephone and broadband communication networks throughout the Solomon Islands.

TTL have recently formed an alliance with the Eco Media Production Group with a shared vision and common goal objectives; to help develop and promote conservation initiatives throughout the region, advocating environmental and humanitarian awareness and enhancing education in the Solomon Islands. TTL will play a significant role in the development and implementation of Eco Media Production Group Pacific Island Initiatives into the future and we welcome Telekom Television Limited aboard as strategic partners for the FISH & PEOPLE School Project and beyond.

 

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