I 
Fishes Killed by the 1950 Eruption of Mauna Loa 
I. The Origin and Nature of the Collections 
W. A. Gosline, V. E. Brock, H. L. Moore, 
and Y. YamaguchE 
The great volcano Mauna Loa plays 
many parts in the Hawaiian community. We 
are here concerned with its role as a fish 
collecting apparatus. The present paper, which 
is the first of a series that will deal with the 
the fishes made available to us by the 1950 
eruption, is limited to an account of the gen- 
eral nature of our collections. 
The Mauna Loa lava flows of June, 1950, 
reached the sea on the Kona coast of the 
Island of Hawaii at three main points (Lig. 1). 
The first two of these flows dwindled to al- 
most nothing a short time after entering the 
water on the morning of June 2. The third 
flow has far greater significance for us. It 
entered the ocean somewhat to the south of 
the other two (at 19°l6'N., 155°55'W.) on 
the afternoon of the same day. Surges of lava 
from this flow continued to pass into the sea 
in quantity through June 4 and in lesser 
amounts through June 7. 
Whenever a heavy surge of lava hit the sea, 
a large amount of steam rose from the surface 
(Lig. 2). Between the peaks of the surges, jat 
least during the later stages of the flow, the 
moving column of lava entered the sea quietly, 
unexpectedly resembling an escalator disap- 
pearing through the floor of a department 
store (Lig. 3) . Apparently the failure to cause 
surface steam at such times was due to the 
cooling and hardening of the outer layer of 
^ University of Hawaii; Territory of Hawaii, Divi- 
sion of Fish and Game; U. S. Fish and Wildlife Service; 
and Territory of Hawaii, Division of Fish and Game, 
respectively. Manuscript received January 17, 1953. 
the lava column into a water-impervious shell 
through which the rest of the lava flowed. 
(Such conduits, now hollow and sometimes 
extending for distances of more than a mile, 
are well-known features of the Hawaiian ter- 
restrial landscape.) Since the molten material 
flowed continuously without ever filling this 
shell, it can be assumed that the lava was 
breaking out somewhere below. Such out- 
breaks presumably produced steam explo- 
sions which could be felt even in a skiff 
anywhere near the flow. However, no steam 
from these assumed outbreaks ever reached 
the surface, nor was this to be expected unless 
they had been very large or very near the 
surface. 
The total amount of lava entering the sea 
from the 1950 eruption was estimated by 
Macdonald and finch (1950: 1) at over 100 
million cubic yards. 
Fig. 1. Land areas covered by the Mauna Loa lava 
flows of 1919 and 1950, Heights above and below sea 
level given in thousands of feet. Diagonally hatched 
areas: 1950 flows; those that entered the sea are num- 
bered in the sequence with which they reached sea 
level. Stippled area: 1919 flow. Redrafted in part from 
Macdonald and Finch. 
23 
