How Do You Weigh A Living Whale?

Credits to Fredrik-Christiansen (Photo from Oceanographic Magazine)

The obvious answer is that scientists can't really use a scale.

For starters, dead whales can weigh as much as 210 kg to a whopping 160 t. Besides, measurements can be inaccurate given the physical distortion of carcasses caused by bloating and deflation.

But scientists have something new in their arsenal.

Something that can be used above the sea...

But first, let’s learn about how whales are weighed in the past.

The only way to get data on the body mass of whales was to weigh dead or stranded individuals. Studying blue whales, for instance, was limited to dead specimens from whaling operations, fisheries bycatch and beach strandings.

This can be especially limiting with scientists boxed from collecting longitudinal data over a whale's lifespan. This has prevented the inclusion of body mass in many studies in ecology, physiology and bioenergetics.

But now scientists can accurately estimate the weight of free-living whales.

The answer? 

Drones.

Scientists took aerial photos of 86 southern right whales off the coast of Península Valdés, Argentina.

The waters were clear and the sheer number of whales gathering every winter to breed allowed for the measurement of both the dorsal and lateral sides of the whales.

With crisp images, they were able to get data for length, width and height.

These values were then plugged into a model (and voila!) an accurate calculation of whales' body volume and mass.

What's more fascinating is that the parameters of the model can be adjusted to estimate as well the size of other marine mammals, an alternative that can be considered over invasive methods.

This discovery opens a lot of doors for research.

For one, they can now explore the growth of known aged individuals to calculate their body mass increase over time and the energy requirement for growth. They can also peek into the daily energy requirements of whales and derive prey consumption.

Weight data can also provide insights on how chronic stressors influence whale survival and how they can produce offspring.

This innovation also paved the way to recreating a 3D mesh of the whale and a full-color 3D model in the works, which can be used for studying movement and for educational purposes.

SeaLifeBase hosts data on the weight of marine mammals, from blue whale to the dwarf sperm whale, the smallest known whale.

Feel free to explore.

Happy learning!

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[1] Christiansen, F., Sironi, M., Moore, M. J., Di Martino, M., Ricciardi, M., Warick, H. A., Duncan, J. I., Gutierrez, R., Uhart, M. M. (2019). Estimating body mass of free‐livingwhales using aerial photogrammetry and 3D volumetrics. Methods in Ecology andEvolution.

[2] EurekAlert! Researchers use drones to weigh wales. Retrieved from  https://www.eurekalert.org/pub_releases/2019-10/whoi-rud100119.php?fbclid=IwAR2aML0gasxOfu2q2IqSwNoax8znfubn0EH36CHKgnz2nhqXi7muvdVjyWI

[3] Jefferson, T.A., S. Leatherwood and M.A. Webber 1993 FAO species Identification Guide: Marine Mammals of the World. Rome, FAO. 320 p. + 587 figures.

A rare and unforgettable sight: The rainbow-colored blanket octopus

What's better than seeing a rare sea creature? 

Well, seeing two of them and capturing them on camera, of course!

The deep sea never fails to amaze us with bouts of often odd and elusive, yet all the more wonderful creatures.

Take the recent sighting of the rare blanket octopus, which the lucky cameraman Joseph Elayani was able to encounter and film in the wild. On a night dive in the open sea at Romblon (Philippines), at depths of 9-22 m [1], he caught sight of not only one but a pair of female rainbow-colored blanket octopus. It was a glorious moment for Elayani as he witnessed the rapidly shifting colors of the arms, from hues of pastel blues and purple to stunning reds and oranges. This change in color is deemed to be the octopus' reaction from the different light levels of the camera or as a strategy to ward off predators [2].

Credits to Joseph Elayani via Cater News

Blanket octopuses are pelagic creatures found in the Atlantic, Mediterranean and the Pacific, in tropical to subtropical waters. They belong to the genus Tremoctopus [3]. It got its name from the sheets of webbing that extend between some of their arms [4]. 

Octopus, in general, are known to be masters of disguise, changing color patters to blend to their environment and escape predators or sneak on their prey or even mimic other species. Blanket octopus, meanwhile, are known to spread their majestic arms out to drive away would-be predators [4].

One of the things that make them odd is the sheer size difference between sexes: while males are less than an inch long, females can grow up to six feet long and weigh up to 40,000 more than males. It's also unusual that they are immune to the stinging cells of the perilous jellyfish Portuguese man-of-war, which it uses as a weapon against predators [4]. 

Current population data on blanket octopus is unknown [4]. For the meantime, immerse in the beauty that these two lovely octopuses have to offer.

We welcome collaboration with marine scientists and enthusiasts alike. If you have more information or photos on blanket octopuses, you can leave us a message at sealifebase[at]gmail[dot]com.

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[1] Good News Pilipinas. Rare rainbow-colored blanket octopus caught on diver’s camera in Romblon waters. Retrieved from https://bit.ly/2Y3HEVL

[2] Best, S. (18 Jun 2019). Stunning rainbow blanket octopuses spotted swimming in depths of ocean. Mirror.  Retrieved from https://bit.ly/2YiRpKU

[3] Turgeon, D.D.; Quinn, J.F. Jr.; Bogan, A.E.; Coan, E.V.; Hochberg, F.G.; Lyons, W.G.; Mikkelsen, P.M.; Neves, R.J.; Roper, C.F.E.; Rosenberg, G.; Roth, B. (1998). Common and scientific names of aquatic invertebrates from the United States and Canada: Mollusks, 2nd ed. American Fisheries Society (Special publication 26), Bethesda, Maryland. 526 p.

[4] National Geographic. Blanket octopus. Retrieved from https://on.natgeo.com/32VuskK

[5] USA Today (4 June 2019). Rare 'rainbow' blanket octopuses caught on camera in the Phillippines | USA TODAY. Retrieved from https://bit.ly/2L92yem

The role of biodiversity in human health

The United Nations has marked May 22 as The International Day for Biological Diversity to raise awareness and understanding of biodiversity issues. 

This year's theme, "Our Biodiversity, Our Food, Our Health," focuses on the invaluable role of biological diversity in human health and well-being. We can show our appreciation for the resources nature provides us every day by truly understanding (or simply reminding ourselves) where we get our resources for good health—the food we eat, the water we drink, and the air we breathe. By doing so, we are putting first the species and the ecosystems that keep our health in check and make our lives worthwhile. 

We can be a catalyst of change in small ways, be it by buying local food or using recyclable bags.

Here in SeaLifeBase, we celebrate marine biodiversity, from foraminiferans to cetaceans, from which we depend a lot for our health and well-being. If you're keen to learn more, visit us here.

Q-quatics welcomes its new researchers!

Two new fresh graduates, Selina De Leon and Fayte Sicnawa, jump on board the Q-quatics team last April 1. They have since been involved in the identification of fishes in partnership with the University of Western Australia and the carry forward of global fisheries catch reconstructions led by the Sea Around Us.

Selina De Leon, a BS Biology graduate, hails from the University of the Philippines Diliman. She took up courses on marine sciences, ichthyology, ecology, biodiversity, and conservation. Selina’s fascination for the ocean started when she saw the iconic BBC documentary series Blue Planet. That made her want to study marine life and experience it up close. Last Aril 2018, she volunteered for the humpback whale research expedition (Balyena.org) in Camiguin Island, Calayan, Cagayan.

Fayte Sicnawa, a member of the Indigenous People of Kalinga, studied BS Biology major in Wildlife Biology at the University of the Philippines Los Baños. Upon graduation, she went on to teach Chemistry, Biology and Environmental Science at Trace College for a year. As a wildlife biologist, she’s aware of the decline in the sheer biodiversity of species in the country. She therefore feels strongly about the need for their conservation. She believes that the training she'll get in Q-quatics would leverage this passion. Today, she’s pursuing a master’s degree in Wildlife Biology.

Welcome aboard,  Selena and Fayte!

Creature feature: Meet the dumbo octopus

Illustration by Maxeen Bayer based on the Disney character Dumbo

Deep in the ocean floor lives an octopus, its common name derived from the Disney character Dumbo who can fly with its big ears. Just as the sky is for the endearing elephant, the dumbo octopus hails from the deep, steering the waters by flapping its ear-like fins [1].

To date, there are 21 known species of dumbo octopus (Grimpoteuthis) [2]. Being bathypelagic animals, they live 13,000 feet below water (or almost 4000 m) and are rarely seen in shallow waters. They live in tropical to temperate latitudes and have been observed in New Zealand, California, Oregon, Philippines, and in other areas [3].

Dumbo octopus comes in different sizes, shapes, and colors. Its average size is 20 to 30 cm (7.9 to 12 inches) in length and its mantle, either U- or V-shaped. Like other families of octopi, their tentacles are umbrella-shaped, characterized by webbing between their tentacles, which help them navigate while swimming and crawling on the surface. Their ear-like lateral fins also help them propel around the water [4].

Grimpoteuthis has large eyes, about a third the diameter of their head, but it has limited use in the eternal darkness of the deep oceans. However, to defend itself against predators, it uses its ability to change color and camouflage against the ocean floor. When it camouflages, the ears emit a different color than the rest of its body [4].

They are carnivorous, eating isopods, amphipods, bristle worms and more. Their mouth is different from their kin, engulfing their prey rather than grinding and ripping [1].

The male octopus has a special protuberance in one of its 8 tentacles used to deliver the sperm to a female octopus, which the octopus stores until conditions are favorable for laying eggs on shells or small rocks on the seafloor. Young dumbo octopi are large when they are born and must survive on their own. They can live for 3 to 5 years [1].

Very little is known about these creatures. If you have more information on dumbo octopus, SeaLifeBase welcomes collaboration. Kindly send us a message at sealifebase(at)q-quatics(dot)org.

Written by Maxeen Danielle Bayer

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[1] Helmenstine, A.M. (2018, April 24). All about Grimpoteuthis, the dumbo octopus. ThoughtCo. Retrieved from https://bit.ly/2W3CUtP

[2] WoRMS Editorial Board (2019). World Register of Marine Species. Available from http://www.marinespecies.org at VLIZ. Accessed 2019-03-15. doi.10.14284/170

[3] Oceana. Cephalopods, crustaceans and other shellfish: dumbo octopus. Retrieved from https://bit.ly/2Jfo2qM

[4] Ocean Conservancy (2018, October 8). Everything you need to know about the dumbo octopus. Retrieved from https://bit.ly/2OAYNBg

[5] National Geographic (2018, October 29). Rare dumbo octopus shows off for deep-sea submersible. YouTube. Retrieved from https://bit.ly/2u9gcEP

World Wildlife Day 2019 celebrates marine life

Photo from UNDP

United Nations World Wildlife Day has been celebrating the sheer diversity of plants and animals for six years now by raising awareness on the threats they're facing through a series of events across the globe. 

Inspired by UN's 14th Sustainable Development Goal (SDGs)—life below water—this year marks the first ever World Wildlife Day to celebrate the huge importance of marine life in our everyday lives. It also commemorates the establishment of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora), a treaty which underscores the protection of all endangered plants and animals.

This event gives the opportunity to highlight critical issues faced by marine life, commend successful initiatives for their conservation and scale up future endeavors towards sustaining them for future generations.

One of the major concerns that this campaign addresses is plastic pollution, in which 57 countries have already vowed to reduce their use of single-use and non-recoverable plastics.  

It's a step further to know more about the marine species we need to protect. And SeaLifeBase hosts this information. If you're keen to dive deep into the threatened non-fish marine species in the Philippines (and around the world), you may visit SeaLifeBase.

Who's Got Jellies in their Gut?

Gelatinous zooplankton, loosely termed as jellyfish, can be found throughout world’s oceans, known to cause large blooms. This group includes scyphozoan jellyfish, siphonophores, ctenophores, salps, pyrosomes, and appendicularians [1]. 

If we were asked who dines on these jellies, we might reserve the term ‘belly-full-of jelly’ to charismatic sea turtles (Dermochelys coriacea, Chelonia mydas) and the ocean sunfish (Mola mola). And it's indeed fitting since an adult leatherback turtle, for instance, ingests an average of 330-kg jellyfish wet mass per day or 73% of its body mass [1]. 

With the rise of new technologies in recent years, however, this exclusivity is no longer true: It turns out that not only such massive marine predators get a chunk of their diet from jellyfish. There’s a whole lot on the table, from birds to fishes to worms, joining the feast [1].

New approaches to study the diet of marine animals such as stable isotope analyses or SIA (getting animal tissues to estimate trophic level), animal-borne cameras, remotely operated vehicles or ROVs, and DNA metabarcoding support the finding that a diverse range of marine predators feed on jellies, not incidentally but targeted [1].  

SIA revealed that jellyfish forms a substantial part of the diet of bony fishes Chloroscombrus chrysurus, Thunnus thynnus, Euthynnus alletteratus, Tetrapterus belone, Xiphias gladius and the green sea turtle Chelonia mydas. 

Animal-borne cameras revealed 42.2% of prey capture for some species of penguins, consuming scyphozoans, salps and ctenophores [1]. 

Metabarcoding showed that jellies make up 20% of food DNA sequences of the two species of albatross, ahead of crustaceans in terms of importance. Meanwhile, next-generation sequencing showed that the endangered European eel Anguilla anguilla has got gelatinous zooplankton in its diet. Seen through powerful ROVs, deep-sea octopus (Haliphron atlanticus) and benthic animals, like echinoderms, crabs, shrimps, amphipods, sea anemones, and worms join the slew of jellyfish predators [1].

Hays et al. 2018 Figure 2A, showing a diverse group of predators worldwide feeding on jellyfish.

Overwhelming evidence of widespread jellyfish consumption throughout the world’s oceans means that jellyfish cannot be simply considered a bycatch, but targeted and opportunistically consumed by many marine predators. However, it's important to note that this shift may be influenced by changing ocean conditions [1]. 

Also, knowing that a growing number of marine life now relies on jellyfish for nutrition signifies their susceptibility to harm, or even death, for mistaking plastic wastes for food [1]. 

These findings are important given that jellyfish holds a huge fraction of the pelagic biomass and have recently increased their abundance worldwide [3]. The study also challenges the common notion that undermines the energetic gain from jellyfish consumption, thus the need to better understand its dietary value [1].

To know more about jellyfishes and other gelatinous zooplankton, visit SeaLifeBase. 

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[1] Hays, G. C., Doyle, T. K., & Houghton, J. D. (2018). A Paradigm Shift in the Trophic Importance of Jellyfish?. Trends in Ecology & Evolution 33(11):874-884. Retrieved from https://bit.ly/2DCvaY7

 [2] Lewis, A. (2011, January 5). Leatherback turtle feeding. YouTube. Retrieved from https://bit.ly/1vo1QO8

Untangling the human-jellyfish connection

Last month's mini-symposium Q-quatics 2019: Road Ahead has been productive, providing a means for Q-quatics to communicate possibilities to execute its fisheries and oceans mandate through collaborations with the global scientific community.

Many participants took an interest in the talk of Lucas Brotz, jellyfish expert and Q-Quatics Cnidaria Scientist, as he shared the ever growing, inevitable relationship of humans and jellyfish today.

Based on a rigorous study Brotz led, jellyfish populations, indeed, have been increasing since 1950: out of the 45 large marine ecosystems (LMEs) analyzed, 62% showed increasing trends [1]. This brought with it changes that we are only now seeing—more reports of children dying from box jellyfish stings [4], swarms of jellyfish regularly interrupting fishing activities [2], jellyfish responsible for massive power failure in Luzon [3], and jellyfish turning into snacks [4]. While the demand for jellyfish for food has increased, huge economic losses are incurred by many related industries [4].

Fig. 1. Map of population trends of native and invasive species of jellyfish by large marine ecosystem (LME) (Source: Brotz et al. 2012)

A regular day for fishermen in Japan, clearing the infestations of Nomura (Copyright: Shin-ichi Uye, Hiroshima University)

Counter-measures to control jellyfish populations have been done but with mixed results. A more apparent move, to exploit jellyfish as food, was seen as an opportunity to deter this global rise. However, as Brotz pointed out, eating our way out isn't the likely solution. Rather, adaptation may be our best approach [4]. 

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Sources:
[1] Brotz, L., Cheung, W. W., Kleisner, K., Pakhomov, E., & Pauly, D. (2012). Increasing jellyfish populations: trends in large marine ecosystems. In Jellyfish Blooms IV (pp. 3-20). Springer, Dordrecht. Retrieved from https://bit.ly/2Ea4tvi

[2] Vince, G. (2012, April 5). Jellyfish blooms creating oceans of slime. BBC. Retrieved from https://bbc.in/2hLG1Cc

[3] BBC (1999, December 11). Jellyfish blamed for Philippines blackout. BBC News.  Retrieved from https://bbc.in/2LHCIv2

[4] Brotz, L. (2019, January 31). Jellyfish and humans - the big picture. Q-quatics 2019: road ahead symposium. 

Q-quatics is looking for a Research Assistant

Quantitative Aquatics, Inc. is a non-stock, non-profit, non-governmental organization established in the Philippines in February 2017. Q-quatics was created to support the assembly and dissemination of key data on living aquatic resources for the development of research tools in collaboration with international partners. As such, Q-quatics manages the global biodiversity information systems FishBase, SeaLifeBase, and the global aquatic biogeography initiative, AquaMaps.

Quantitative Aquatics, Inc. seeks a Research Assistant to work in a project funded by the Minderoo Foundation Pty Ltd, in collaboration with the Sea Around Us and the University of Western Australia. 

Q-quatics holds a mini-symposium

Q-quatics launches its year with a mini-symposium held at IRRI Training Center in Los Baños, Laguna last January 31. Local and international marine scientists shared emerging issues on fisheries: from (1) small-scale fisheries academy in Senegal, to (2) global assessment of exploited marine fisheries, to (3) a new analysis of global freshwater finfisheries, to (4) ballast water management, to (5) jellyfish-human relationship, to (6) the use of global databases as identification tools, and (7) the FAO global record of stocks and fisheries. If you're keen to know more about the symposium, you may read Mundus maris piece here. 

Participants, both local and international—UPLB, UP Diliman, BFAR-NFRDI, NAST, National Museum, Haribon Foundation, RARE, ASEAN Center for Biodiversity, Amanpulo Resort, Oceana Philippines, Wetlands International and IRRI—contributed to a lively and productive discussion.

Cornelia E. Nauen, Q-Quatics Board of Trustee

Speakers: Top left to right: Dr. Maria Lourdes Palomares, Dr. Peter Sorensen, Dr. Benjamin Vallejo Jr.;
Bottom left to right:  Dr. Lucas Brotz, Mr. Rodolfo Reyes Jr. and Dr. Nicolas Bailly

This event became an avenue to conceive possible projects, form partnerships and strengthen existing ones with different organizations. These possibilities include the next steps inherent to the declaration of ASEAN being a "safe risk area" for international shipping, call for increased awareness in the importance of freshwater fisheries, conducting jellyfish population studies in the Philippines, and developing machine learning tools for fish identification.