ECOLOQICAL STUDIES AT LOUQH INE
221
clear from the temperature of the inflow water (Fig. 13) that this amount
will be relatively small.
We have not studied the hydrography of the North Basin. The shortest possible time for complete replacement, on the assumption that
there is no mixing and no loss of new (that is South Basin) water, is
about twenty-two tides. With complete mixing about 90% of the North
Basin water would be replaced by South Basin water in twenty-six or
twenty-seven tides. It is possible that some parts of the North Basin
may require much longer for a comparable renewal.
4. The Very Shallow Sub-Tidal Areas
The investigation at Lough Ine is much concerned with the fauna and
flora of the margins of the iough, from low water down to a depth of
1 or 2 m below that level, so that some consideration of the environmental conditions in the “shallow sublittoral” is needed. Unfortunately
only preliminary studies are available. The quantity and nature of
sediment on sub-tidal rocks has not been determined, although one can
see without any precise measurement that rock surfaces on the open
coast and in the mouth of Barloge Creek are clean, but that within the
lough, except where there is appreciable current, they carry a film of
fine sediment which becomes thicker with increasing depth until a t a
depth of a few metres any rocks present are buried in mud. As in
Codium Bay, stagnant conditions are likely to develop locally and in
crevices between boulders over mud. Measurements of oxygen saturation made on a number of samples from positions 5 cm above the bottom, collected in July 1960, ranged from 78% to 122%. Goleen mud
smells of H,S.
Very little fresh water runs into the lough. Small streams enter a t
the northwest corner, where a film of water of low salinity spreads over
the surface, at Rookery Nook (northeast corner of lough), and near
Whirlpool Cliff (drips only), and at the head of the Goleen. There is less
opportunity for the fresh water to become diluted and dispersed in the
enclosed Goleen, and after heavy rain we have found salinities as low
as 3 4 ~ 0 % ~
a t mid-Goleen, and 30.0%, at upper Goleen. In other parts
of the lough, in July and after heavy rain, salinities ranged from 3 4 ~ 3 % ~
Extremes of temperature also occur in the Goleen, especially when
low water is in the afternoon. We have recorded 25°C in the shallow
inter-tidal water of the upper Goleen, and 19-55OC sub-littorally at East
Goleen. Under similar conditions the temperature sometimes rises above
16°C in the shallow waters at North Wall and along the north side of
Castle Island.
to 34.9%,.
€ I *
221
clear from the temperature of the inflow water (Fig. 13) that this amount
will be relatively small.
We have not studied the hydrography of the North Basin. The shortest possible time for complete replacement, on the assumption that
there is no mixing and no loss of new (that is South Basin) water, is
about twenty-two tides. With complete mixing about 90% of the North
Basin water would be replaced by South Basin water in twenty-six or
twenty-seven tides. It is possible that some parts of the North Basin
may require much longer for a comparable renewal.
4. The Very Shallow Sub-Tidal Areas
The investigation at Lough Ine is much concerned with the fauna and
flora of the margins of the iough, from low water down to a depth of
1 or 2 m below that level, so that some consideration of the environmental conditions in the “shallow sublittoral” is needed. Unfortunately
only preliminary studies are available. The quantity and nature of
sediment on sub-tidal rocks has not been determined, although one can
see without any precise measurement that rock surfaces on the open
coast and in the mouth of Barloge Creek are clean, but that within the
lough, except where there is appreciable current, they carry a film of
fine sediment which becomes thicker with increasing depth until a t a
depth of a few metres any rocks present are buried in mud. As in
Codium Bay, stagnant conditions are likely to develop locally and in
crevices between boulders over mud. Measurements of oxygen saturation made on a number of samples from positions 5 cm above the bottom, collected in July 1960, ranged from 78% to 122%. Goleen mud
smells of H,S.
Very little fresh water runs into the lough. Small streams enter a t
the northwest corner, where a film of water of low salinity spreads over
the surface, at Rookery Nook (northeast corner of lough), and near
Whirlpool Cliff (drips only), and at the head of the Goleen. There is less
opportunity for the fresh water to become diluted and dispersed in the
enclosed Goleen, and after heavy rain we have found salinities as low
as 3 4 ~ 0 % ~
a t mid-Goleen, and 30.0%, at upper Goleen. In other parts
of the lough, in July and after heavy rain, salinities ranged from 3 4 ~ 3 % ~
Extremes of temperature also occur in the Goleen, especially when
low water is in the afternoon. We have recorded 25°C in the shallow
inter-tidal water of the upper Goleen, and 19-55OC sub-littorally at East
Goleen. Under similar conditions the temperature sometimes rises above
16°C in the shallow waters at North Wall and along the north side of
Castle Island.
to 34.9%,.
€ I *