Introduction

Until recently it was believed no life could exist without the direct or indirect presence of light. This theory was held in quite high regard in marine science. Edward Forbes, a prolific and well respected marine biologist of the 19th century, theorized no life could exist below 550m with his paper – Deserts on the seafloor, Edward Forbes and his Azoic hypothesis for a lifeless deep sea. Crucial life limiting factors such as light availability, nutrition, temperatures and pressure where all observed to decrease, bar pressure which increases, with depth. Errors made in the original theory and lack of deep sea exploration were the basis for a common misconception which lasted for many years Recent discoveries have however helped us to shed this incorrect theory. In 1977, deep sea hydrothermal vent system were found, at a depth of approximately 2500m In the Galapagos rift valley showing new and alternative life not yet previously discovered (Jannasch & Mottl 1985) The newly discovered vent system supported a seemingly large community of benthic organisms. At a depth of 2500m, 1950m deeper than Forbes had declared possible for life to exist. How did these organisms survive? how was the ecosystem supported? And what adaptations had they to live in such a location; these questions were faced by marine scientists of the day  

 The sections of this blog will focus on answering these questions in relation to a number species or groups found at differing trophic levels of the hydrothermal vent community.  A typical food chain model (Figure 1) will be used to clearly show the information:  

  1. Primary producer

-          Chemoautotrophic Bacteria  

  1. Primary consumer (due to symbiosis of bacteria, some species will be included within this section that do not directly feed upon the primary consumers, but still benefit directly from their presence)

-          Riftia Pachyptila (Vestimiferan tube worm)  

-          Lepetodrilus elevates (Grazing limpet species)  

  1. Secondary consumer

Thermarces Cerberus (predatory benthic fish)   

    

   

Figure 1 - Simple food chain model

 

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