Land of the Holy Places

The scenery at Pohnpei is nothing short of spectacular; seldom does any image suffice. Nevertheless, we have arrived and little, if anything, has changed which in itself makes Pohnpei so endearing; a visual archive of biodiversity if you will. This seeming endless cacophony of biodiversity defines Pohnpei as one of the world's "centers of botanical endemism" largely due to being one of the rainiest places on earth (~300 inches/762 cm of rainfall per annum). This year, being an El Niño, surpasses itself, with the assurance that the following year will typically be much drier! 

Cultural_Curiosities_Above_&_Below_2015_BLOG.jpgFigure 1. From left to right: Sokehs (or Paipalap) Rock at Pohnpei where tales of magicians, geysers, tsunami's, and sea sponges adorn!! Diver dwarfed by a wall of coral at Pakin Atoll (5 - 35 m/16 - 115 ft). The hugely biodiverse mesophotic walls of Ant Atoll (135 m/443 ft). Images by SJ. Rowley.

In addition to Sokehs Rock, Pohnpei is riddled with cultural curiosities, hearsays, and archeological delights (e.g., Nan Madol) that have evolved over centuries of differential survival methods between high island cultures and low-lying atoll communities across the Pacific. But where man has inhabited these regions for arguably 2.5 My nature has been beavering away in excess of 30,000 My. It is the evolution of nature's creativity, through diversification, that leads to an immense level of biodiversity at such remote and unchartered depths. And the unknown biodiversity at these depths is what we are here to explore.

Deep_&_Shallow_blog_2015-s.jpgFigure 2. Biodiversity in the shallow waters (above) at Pohnpei in the depths (below) at Ant Atoll (100 m/328 ft). Images by SJ. Rowley.

Frequently coined the "rainforests of the ocean", coral reefs are centers of marine biodiversity. It is thought that a substantial proportion of these reefs (~80%) actually exist and persist from depths of 30 to over 150 m (100 - 500 ft). These deeper depths are essentially a different ecosystem, the mesophotic coral ecosystem (MCE), and are typically characterised by a diverse array of fauna and flora, which in many ways appear specialised to the attenuation of light and wave action, and the many fluctuations in temperature, dissolved oxygen, water flow, and nutrients. Therefore, MCE's evoke the discovery of species and behavioural interactions new to science. But also, MCE's may likely hold fundamental keys to questions of persistence through novel adaptative strategies, which have evolved over time. This is most fascinating; what will we find, how did they get there, by what, mechanisms did they survive, persist, and ultimately evolve?Gray_Tip2[PS]_BLOG.jpgFigure 3. A young Grey Reef Shark (Carcharhinus amblyrhynchos (Bleeker, 1856)), Palikir Pass, Pohnpei. Image by SJ. Rowley. 

We are here to characterise the undescribed mesophotic reefs of the atolls, Ant and Pakin, in addition to Pohnpei Island. Technological advances in closed circuit rebreather (CCR) diving facilitates this research at depths that are previously unknown and a significant challenge to investigate requiring submersible, remotely or autonomous underwater vehicles, or surface supply. The beauty of CCR diving is the liberty at which one can intimately experience the natural world, and where human observation, dexterity, and understanding can be utilised to test mechanisms of survival over ecological and geological time. 

Pakin_Atoll_SRF_2015-2.jpgFigure 4. Pakin Atoll from sunrise (top) to surface waters from 60 m (197 ft) depth (middle image), and BD Greene (bottom) catching Parapercis n.sp., at 135 m (443 ft) depth. Images by SJ. Rowley.

The objectives of this research trip were four-fold: 1) exploration of the deep reefs of the Senyavin Islands (Pohnpei Island, and the atolls Ant and Pakin), 2) systematic of two key mesophotic groups; gorgonian corals and fishes, 3) experimental procedures on the gorgonian species at depth, with all leading to 4) ecosystem conservation management opportunities through local community collaboration.

SRF_FIGURE6_Sonia_Sounihrek_Chief_Pakin-s.jpgFigure 6. SJ. Rowley teaches chief Sounihrek Pakin and his community how to identify gorgonian species and play ‘count the associate brittle stars’ with the children. Image by J. Hartup.

It is essential to disseminate what we find. Furthermore, it has become increasingly clear that bringing about awareness of these mesophotic ecosystems provide a valuable perspective to the local communities who didn't even know that was there. Pohnpei is defined as and believed to be the Land of Holy Places (Faun pei; Brigham 1900). To the local communities at least, therefore, our work enables that belief to grow in depth and meaning with each dive that we do.

This research was generously supported by: 

Ocean First Education

Systematics Research Fund

Edmondson Fund


Adapted from Rowley SJ. 2015. Land of the Holy Places. 20th August 2015.