467 



We are thinking also of the use and problems relating to diving 

 physiology, hyperbaric medicine. These are the areas that we are try- 

 ing to point up when we use the term biomedical oceanography, 



I think we can illustrate this a little more graphically if I can show 

 these pictures and if the gentlemen are ready with the projectors. I 

 would like to show you this first film on some of the hazards that we 

 encounter in the area of toxic marine organisms. 



]Most of this material has now been documented based on what now 

 amounts to a 2 5 -year study. This study was under the sponsorship of 

 many different Federal and private agencies. 



I have with me this morning two of these volumes on "Poisonous and 

 Venomous Marine Animals of the World" which I wrote. There is a 

 third volume that will be out late this fall on the subject of poisonous 

 and venomous marine animals. Please keep in mind that this is only 

 ■one segment of the overall field of biomedical oceanography. These 

 volumes contain over 3,000 pages of documentation on one aspect of 

 hiomedical oceanography. 



Mr. KoGEEs. Excuse me. 



Come ahead and set up your projectors and the doctor will proceed 

 with his testimony as you are setting it up. 



Dr. Halstead. I would like to point up the relationship that exists 

 between what we might term biochemical agents, nutrients, marine 

 pharmaceuticals, and toxins. 



When we talk about nutrients, when we talk about marine phar- 

 maceuticals, and when we talk about toxic agents, basically we are 

 talking about biologically active products. 



In other words, we are talking about a substance that either when 

 ingested or when injected produce some sort of a reaction, some sort 

 of an effect in a human or an animal. If we look at the subject of drugs, 

 we find that a drug is really not effective and it is really not of any 

 commercial value unless this drug does have some sort of biological 

 acti"\dty. 



When we have a therapeutic agent in sufficient concentration — we 

 •can take almost any of our antibiotics as an example of this — we can 

 actually produce a toxic reaction. 



There is a direct relationship between drugs on the one hand and 

 toxic substances on the other. So when we undertake a fundamental 

 study in the area of marine biotoxicology, biological poisons produced 

 by marine organisms, we actually have a groundwork as it were for 

 the entire area of marine pharmaceuticals. 



We also find that there is a relationship between pharmaceutical 

 products, toxic agents, and foods from the sea because in some in- 

 stances, as you will see in this first motion picture, some of the orga- 

 nisms that we would like to use as food and which are usually edible 

 under certain circumstances may become very toxic and in this first 

 film you will see an example of this. 



Here is a red snapper, a valuable food fish, Lutjanus vaigiensis, a 

 member of the snapper family. 



In this case we had a fish which^ because of its food habits and be- 

 cause of the environmental conditions that existed in this particular 

 island area, within a very short period of time became violently 

 poisonous. 



