218
N. A. HOLME
Rbertleen grab
0.1 in2
4 cm (Smith and McIntyre,
Holme sampler
0-05 m2 4-5 cm (Holme, 1949)
(later models taking samples 2 x 0.1 ma dig to
about the same depth)
and other sizes
1954)
Okcan grab*
0.25 m2 1 5-10 cm
Orange-peel
Various
? 5-10 cm
grab
sizes
N.B. Penetration distances for the grabs are the average depth of
sampling (equal to volume of sample in litres per 0.1 m2. The
maximum depth of bite is rather greater (see p. 242, and
Birkett, 1958).
C. Sampling the deep-burrowing fauna
Samplers penetrating more than 15 cm in firm sand.
1. Qualitative
Very heavy dredges such as the ring dredge described by
Gustafson (1934).
2. Quantitative
Forster anchor-dredge. The original model, used from a
small boat will dig in deeply without dragging along the
bottom. - Although wedge-shaped, the sample may be
considered pemi-quantitative, Penetrates to about 20 cm.
Besides these, there are a numbcr of coring tubes which under
favourable circumstances may pelletrate at least 15 cm. These include
Otto Yetterson’s sampler (Petter.wn, l928), and the “ vacuum ”
corer described by Holme (1953). These samplers might be used for
comparative hauls for calibrating other instruments, but would not be
used €or routine work a t sea.
Knudsen sampler. Sampling area 0.1 m2, depth 25-30 em.
D. Sampkrs for special purposes
1. 1cI icrofau?tas
This subject has been covered in some detail by Thorson (1957a).
One of the commonest requirements is for a narrow core p e r h a p
* Although Lisitsin and Udintsev (1955) write that the Okean grab takes sampler
UP to 25-30 cm in a n d and gravel deposits. they give no more precim details. Belyayev
(l962), however, in his study of cephalopod beaks in oceanic deposits, reports that the
0-26 nin Okean grab usually sampled soft deposits to a depth of about 15, or occasionally
20 cm-
N. A. HOLME
Rbertleen grab
0.1 in2
4 cm (Smith and McIntyre,
Holme sampler
0-05 m2 4-5 cm (Holme, 1949)
(later models taking samples 2 x 0.1 ma dig to
about the same depth)
and other sizes
1954)
Okcan grab*
0.25 m2 1 5-10 cm
Orange-peel
Various
? 5-10 cm
grab
sizes
N.B. Penetration distances for the grabs are the average depth of
sampling (equal to volume of sample in litres per 0.1 m2. The
maximum depth of bite is rather greater (see p. 242, and
Birkett, 1958).
C. Sampling the deep-burrowing fauna
Samplers penetrating more than 15 cm in firm sand.
1. Qualitative
Very heavy dredges such as the ring dredge described by
Gustafson (1934).
2. Quantitative
Forster anchor-dredge. The original model, used from a
small boat will dig in deeply without dragging along the
bottom. - Although wedge-shaped, the sample may be
considered pemi-quantitative, Penetrates to about 20 cm.
Besides these, there are a numbcr of coring tubes which under
favourable circumstances may pelletrate at least 15 cm. These include
Otto Yetterson’s sampler (Petter.wn, l928), and the “ vacuum ”
corer described by Holme (1953). These samplers might be used for
comparative hauls for calibrating other instruments, but would not be
used €or routine work a t sea.
Knudsen sampler. Sampling area 0.1 m2, depth 25-30 em.
D. Sampkrs for special purposes
1. 1cI icrofau?tas
This subject has been covered in some detail by Thorson (1957a).
One of the commonest requirements is for a narrow core p e r h a p
* Although Lisitsin and Udintsev (1955) write that the Okean grab takes sampler
UP to 25-30 cm in a n d and gravel deposits. they give no more precim details. Belyayev
(l962), however, in his study of cephalopod beaks in oceanic deposits, reports that the
0-26 nin Okean grab usually sampled soft deposits to a depth of about 15, or occasionally
20 cm-