Tag: oceans

Save the Nautilus! Three new species described from the Coral Sea and South Pacific

The enigmatic animals with beautiful shells are facing population declines and, possibly, even extinctions due to the activity of unregulated fisheries.

Guest blog post by Dr Gregory Barord, marine biology instructor at Central Campus and conservation biologist at the conservation organization Save the Nautilus

Nautiloids were once quite plentiful throughout the oceans, based upon the fossil record. Today, they are represented by just a handful of species, including the newly described Nautilus vitiensis of Fiji, Nautilus samoaensis of American Samoa, and Nautilus vanuatuensis of Vanuatu. These descriptions highlight the concept of allopatric speciation, or biogeographic isolation, where populations are geographically separated from other populations, resulting in a barrier to gene flow. Over time, these populations may eventually evolve into distinct species.

Nautilus samoaensis.
Nautilus trap construction. Photo by Gregory Barord

But what does it take to be able to collect the evidence needed to determine if three different populations of nautiluses are in fact three different species? For me, this is the best/worst part of the overall process, because nautilus fishing is not easy. For our team, it starts with building large, steel traps that are about a meter cubed. Then, we wrap the steel frame (ouch), with chicken wire (ouch) mesh (ouch), create an entry hole (ouch), attach it to a surface buoy with about 300 meters of fishing line, and bait it with (ouch) raw meat, usually chicken! Trap construction may take place on a nice beach or a bit inland in the rain or in a warm warehouse. Wherever it takes place, you will have some memories, I mean little scars, on your hands from working with the chicken wire. Looking down at my hands right now, I can remember where I was by looking at each of those scars… worth it!

Tossing the traps into the sea at dusk is the easy part. Load them on the boat, find the right depth, and tip them over the side of the boat. The hard part is retrieving the traps the next day, after about 12 hours of the raw chicken scent moving through the currents. There are a number of methods we’ve used to pull the traps up, from mechanical winches, hand-powered winches, float systems, boat pulls, and of course, just pulling with one hand at a time. Invariably, something happens in each location where we are just pulling the trap up from 300 meters one meter at a time, which takes a good half hour at least. But, at least you are getting a VERY good work-out. Eventually, you see the trap and these white little orbs in it and you know you’ve caught some nautiluses and the pulling is almost done, for now.

Nautilus trap in water with nautiluses in it. Photo by Gregory Barord

The next step might be my favorite. One of us jumps in the water and free dives about 5 meters to carefully (ouch, that chicken wire) reach for the nautiluses in the trap and bring them to the surface. You are face to face with these uniquely, misunderstood organisms who seem like this is just another day for them. For me, this is exhilarating! Once on the boat, they are placed in chilled seawater and from then on, the data collection happens fast. With the living organism in hand, you can start to glean even more of the differences between the species, examining the hood ornaments, or lack thereof. After some photos, measurements, and non-lethal tissue samples, the nautiluses are released and burped.

Nautilus vanuatuensis.

Maybe nautilus burping is my favorite part. To do this, we either dive with SCUBA or free dive with the nautiluses, and ensure there are no air bubbles trapped in the shell that may cause them to be positively buoyant. Imagine, you have one nautilus in each hand and you start swimming down, your feet and the nautilus tentacles pointed toward the surface. At a sufficient depth, you release them and observe their buoyancy. As the nautiluses compose themselves and jet back down to their nektobenthic habitat 300 meters below, you realize you may never see that individual nautilus again, and that nautilus may never see another human, well, maybe they will…

For me, the impetus for this publication in ZooKeys is rooted in nautilus conservation efforts. Over the last 20 years, I have studied nautiluses from many angles and for over 10 years now, have worked with an international team of folks to address nautilus conservation issues. For many nautiluses, probably millions, they were caught in much the same way that our team collected nautiluses. However, their first meeting with humans was their last as they were pulled from the trap, ripped from their protective shell, and tossed back in the ocean, used as bait, or, rarely, consumed. The shell is the attractive piece for shell traders and the living body has no value. It is like shark finning in that sense. As a direct result of these unregulated fisheries, populations of nautiluses have crashed, some have reportedly gone extinct, and international and country level legislation and regulations has been enacted.

A nautilus shell shop. Photo by Gregory Barord
Nautilus vitiensis.

Currently, there are no known fisheries in Fiji, American Samoa, or Vanuatu so the risk of these populations decreasing from fisheries is low, at the moment. Now, what is the risk to these same populations from ocean acidification, increased sedimentation, eutrophication, warming seas, and over-fishing of other species connected to the ecosystem nautiluses reside in? Right now, we simply do not know. Our conservation efforts started with simply counting how many nautiluses were left in different areas across the Indo-Pacific, then recording them in their natural habitat, then tracking their migrations, and now describing new species. There are still many questions to address regarding where they lay eggs, what they eat, and how they behave.

All nautiluses have long been grouped together when describing their natural history, but as we continue to uncover the nautilus story, it is increasingly obvious that each population of nautiluses is different, as exemplified by these three new species descriptions. This is certainly an exciting time for nautilus research, as we uncover more and more information about the secret life of nautiluses. I just hope that this is also an exciting time for nautiluses as well, and they continue doing their nautilus thing as they have done for millions of years.

The first Field Identification Guide of Seychelles’ deeper reefscapes

The deep ocean is the last frontier on our planet. It is home to creatures beyond our imagination and filled to the brim with life. Coastal communities have known the value of a healthy ocean for centuries, yet much of its life remains unknown, sitting beyond the reach of most research programs due to the hostility of its depth and vastness. With current research and monitoring activities in the region mostly focussing on shallow reefs, our Field Identification Guide, published in the peer-reviewed, open-access Biodiversity Data Journal, aims to showcase the benthic organisms that inhabit the Seychelles’ deeper reefscapes. The research cruise that gathered the imagery data used to create the guide, Nekton’s “First Descent: Seychelles Expedition”, was the first of its kind to systematically survey deeper reefs in Seychelles waters, bringing to light previously little-known ecosystems and their inhabitants.

Guest blog post by Nico Fassbender, Zoleka Filander, Carlos Moura, Paris Stefanoudis and Lucy Woodall

 “We cannot protect something we do not love, we cannot love what we do not know, and we cannot know what we do not see.”

These compelling words by author Richard Louv perfectly describe the importance of taxonomy in today’s conservation efforts.

A fan coral of the genus Annella surrounded by various smaller fans and encrusting benthic organisms. Photograph taken at 60m depth. © Nekton.

The deep ocean is the last frontier on our planet. It is home to creatures beyond our imagination and filled to the brim with life. Coastal communities have known the value of a healthy ocean for centuries, yet much of its life remains unknown, sitting beyond the reach of most research programs due to the hostility of its depth and vastness. 

More recently, the importance of deeper ecosystems started moving into the focus of modern marine research as many scientists across the globe are now working to unriddle the mysteries and processes that drive the patterns of life down in the deep.

Deeper reef habitats, starting at ~30m depth beyond SCUBA diving limits, are of crucial importance for coastal communities and adjacent ecosystems alike. They have been found to not only support coral and fish larval supply, aiding shallower reefs, but also to act as a refuge for many species in times of disturbance. Yet, going back to the start of this post – you cannot protect what you don’t know – and we currently know very little about these deeper reefs, especially ones in the Western Indian Ocean region.

We are many nations, but together we are one ocean.

Zoleka Filander – Department of Forestry, Fisheries and Environment, Branch Oceans and Coasts, Cape Town, South Africa

With current research and monitoring activities in the region mostly focussing on shallow reefs, our Field Identification Guide, published in the peer-reviewed, open-access Biodiversity Data Journal, aims to showcase the benthic organisms that inhabit the Seychelles’ deeper reefscapes. The research cruise that gathered the imagery data used to create the guide, Nekton’s “First Descent: Seychelles Expedition”, was the first of its kind to systematically survey deeper reefs in Seychelles waters, bringing to light previously little-known ecosystems and their inhabitants.

All species play relevant roles in trophic relations, in the functioning of ecosystems, and all have a potential biotechnological interest.

Carlos Moura – OKEANOS/DOP, University of the Azores, Horta, Portugal
A grouper (Cephalopholis miniate) hovering above encrusting benthic communities at Aldabra, dominated by the scleractinian coral Pachyseris. Photograph taken at 30m depth. © Nekton.

Our Field Identification Guide is one of the first efforts to describe the mesophotic and sub-mesophotic reefs in the Western Indian Ocean. To effectively protect these ecosystems, stakeholders need to be able to visualise them and scientists need to be able to identify and classify the organisms they observe. Displaying the diversity of the benthic organisms we encountered is only the first step in a complex and long process, allowing us to categorize, study, monitor and thus effectively protect these habitats. 

The correct identification of life is a fundamental building block of ecological knowledge. This international collaboration provided an important place to start from when considering the life on deeper reefs in Seychelles and the wider Western Indian Ocean region.

Lucy Woodall – University of Oxford, and Nekton

To survey the benthic flora and fauna of the Seychelles, we used a variety of methods, including submersibles, remotely operated vehicles and SCUBA diving teams equipped with stereo-video camera systems. We then recorded benthic communities during transect surveys conducted at 10 m, 30 m, 60 m, 120 m, 250 m and 350 m depths. This way, we ended up with 45 h of video footage and enough images to be able to present a photographic guide for the visual identification of the marine macrophytes, corals, sponges and other common invertebrates that inhabit Seychelles’ reefs.

We encountered coral fan gardens on steep slopes, boulders entirely encrusted with sponges of all colours and textures, corals of all shapes and sizes, and an amazing variety of critters. The images in our guide cannot do justice to the beauty of these habitats, and more than one tear was shed encountering these intact ecosystems teeming with life. Especially in times of increasingly frequent disturbance events and quickly shifting baselines (i.e., what we would see as a pristine, healthy reef in the 21st century), intact reef systems become increasingly rare. So much so that they are often confined to extremely remote and/or long and heavily protected areas. Finding these deeper reefs intact and with little to no signs of anthropogenic disturbance means hope – hope that there are yet undiscovered and unexplored reefs in the Western Indian Ocean region that show similar traits; and hope that we will discover even more novel habitats worth protecting.

An overview of how habitat composition changes across depths at Astove Island. © Nekton.

We hope that this guide will help the public to discover the beauty of Seychelles’ deeper reefs and aid current and future monitoring and research activities in Seychelles and the Western Indian Ocean region.

Currently, there are few formalised training materials available to new marine researchers working in mesophotic and deeper reef habitats, especially for the Indian Ocean. The present benthic field ID guide will hopefully be of use to marine researchers, managers, divers and naturalists with the identification of organisms as seen in marine imagery or live in the field.

Paris Stefanoudis – University of Oxford, and Nekton

Taxonomic paper:

Fassbender N, Stefanoudis PV, Filander ZN, Gendron G, Mah CL, Mattio L, Mortimer JA, Moura CJ, Samaai T, Samimi-Namin K, Wagner D, Walton R, Woodall LC (2021) Reef benthos of Seychelles – A field guide. Biodiversity Data Journal 9: e65970. https://doi.org/10.3897/BDJ.9.e65970