gs are off the lead), jet skiing, boating, kayaking, surfing, windsurfing, kite surfing, low flying aircraft, sunbathing, fishing, shellfish collecting, horse-riding, birdwatching and photography can keep birds from resting or feeding for periods of time. Away from the beach other activities can be detrimental to birds in their breeding grounds such as hill walking and off road vehicles.
Uncontrolled domestic animals such as dogs and cats can cause great loss or distress to ground nesting and roosting birds. Recently horse training on beaches has become a problem in some parts of Australia.
Loss of food supply
The principle cause of food shortage is habitat loss, and also climate change is having a greater effect but our direct actions can cause problems too. Shellfish, in uncultured populations, can become over harvested; this is one of the probable causes of the demise of the Canarian Black Oystercatcher.
Another excessive use of the fruits de mer was in the over exploitation of Horseshoe crabs in the Delaware Bay in North America for fishing bait. Stocks of these bizarre creatures fell drastically depriving migrant waders, which were heading for their breeding grounds, of vital feeding opportunities.
The destruction of fisheries also has a knock on effect on the balance of nutrients in the sea which can result in ecosystems collapsing.