The Characteristics of a Sandy Shore at Pallarenda Beach, Townsville, North Queensland

The characteristics of a sandy shore at Pallarenda beach, Townsville, North Queensland.

Introduction:

The sandy shores of beaches can be considered as a very harsh environment to live in (Ted Klenk, 1999). Survival in such a habitat requires an organism to withstand strong wave and current action, tidal rise and fall, unstable substrate, heavy predation and wide variations in salinity and temperature (The Otter Island Project). Any organism found in this type of harsh environment is specialized and highly adapted (The Otter Island Project).

Fine, sandy beaches often occur in areas with light wave action (California's Ocean Resources, 1995). While a more coarse sand is found with heavy wave action (California's Ocean Resources, 1995). The slope gradient of a beach also helps determine the grain size of the sediment (Bascom, 1959). The steeper a beach is, the larger the sand particles (Ted Klenk, 1999). The water retention of coarse sand is quite low allowing temperatures to rise easily at low tide (MB2050 lecture notes). Any organisms on a coarse particle beach will not only have to deal with the very unstable substrate but also the real danger of desiccation (MB2050 lecture notes).

Fine sediment areas do not have much water moving through the particles (MB2050 lecture notes). Therefore any oxygen available is used up quickly by burrowing organisms (MB2050 lecture notes). There comes a point beneath the substrate where there is insufficient oxygen for organisms to respire, this is called the anoxic layer (MB2050 lecture notes). The anoxic layer is therefore much deeper under coarse sediments then fine (MB2050 lecture notes).

The fish community of a surf zone is largely controlled by three factors (Robertson & Lenanton, 1984). The form of primary production input to the surf zone, the water movement pattern, and the geomorphology of the sandy beach (Robertson & Lenanton, 1984). Fish such as anchovies, herrings and mullets often inhabits surf zones around the world (The Otter Island Project).

The aims of this experiment were to examine physical features and sediment-related characteristics of Pallarenda beach and the influence of these characteristics on the occurrence and distribution of the intertidal taxa. This experiment also aimed to describe the fauna in the surf zone region of Pallarenda beach.

Materials and Methods:

The beach studied during this experiment was Pallarenda Beach just North of the city of Townsville in North Queensland. The co-ordinates of the location were 19o11.8’S, 146o46.6’E. The beach experiences a tropical climate, the experiment was carried out on the 4th of March in the year 2000 after much rainfall.