The Transect Line – March/April 2016

The Pacific seahorse, Hippocampus ingens, is currently listed as a vulnerable species by the International Union for the Conservation of Nature’s (IUCN) Red List of Threatened Species and with a size of about 12 inches, it is one of the largest seahorse species you will find around the world.

This subtropical fish comes in a variety of different colors including gray, brown, red and yellow, which often match the color of the surrounding habitat that they live in. They can normally be found in shallow beds of soft corals and gorgonians in the Eastern Pacific region and they’re unique in the fact that they’re the only seahorse species that can be found along the California Coast, reaching San Diego Bay. Its normal range extends southward to Peru.

There’s a very large demand for dried seahorses in Asia and other places around the world because they have been used as medicine for thousands of years. Each year, tons of Pacific seahorses are caught, dried and shipped to these countries. As the population on the planet increases, the demand for seahorses grows and the number of this species continues to decline, making them a rare sight to be seen even throughout their normal distribution range.

With the influx of unusually warm water that’s been brought in by this year’s El Niño event, local divers have been seeing some very rare species while diving in Southern California, including the Pacific seahorse. They have recently been spotted in San Diego and as far north as the waters of Alamitos Bay in Los Angeles County, which is the farthest north this particular species has ever been sighted before.

Seeing seahorses in California is definitely unusual, but there are two reasons why an El Niño event could bring them into the waters of Southern California. First, the increased water temperature associated with El Niño could allow them to temporarily expand their range further north. Second, water from the western Pacific is brought towards the American coastline due to the reversal of the Walker cell, a phenomenon that occurs during an El Niño event. This process could potentially transport a seahorse attached to some seaweed drifting in the open ocean into California waters. With this recent increase in Pacific seahorse sightings in Southern California, we may get the chance to see one during the upcoming survey season this year!

Win a place to join a unique SCUBA diving coral reef conservation expedition to Oman, the Maldives or Malaysia!

In partnership with Reef Check and the Marine Conservation Society, Biosphere Expeditions is offering a free place on an expedition to Musandam (Oman), the Maldives or Tioman Island (Malaysia). Each trip includes training and certification as a Reef Check EcoDiver. And there's more: in addition to the expedition prize, there are other prizes from Reef Check and the Marine Conservation Society to be won.

You have to be a qualified diver (minimum PADI Open Water or equivalent). You also have to be prepared to muck in on a hands-on conservation project, not a luxury dive holiday. If this is you, then tell us who you are, why we should take you on and what you think you can contribute to the diving expedition.

More information and the application form is at http://www.biosphere-expeditions.org/competition

Good luck!

Last month, Reef Check, AltaSea at the Port of Los Angeles and the Los Angeles Maritime Institute (LAMI) announced a collaborative partnership to engage youth in marine conservation through a highly interactive Student Ocean Scientist Program (SOS). The acronym reflects the urgent need to address threats to marine life locally and globally, and is designed to raise awareness about the value of ocean resources, threats to ocean health and solutions to those problems.

For the pilot phase, the STEM-based program will focus on Title I middle schools located in Los Angeles County on a first-come, first-served basis. During each three-hour program, students are introduced to the local marine ecosystem in the Los Angeles Harbor aboard one of LAMI's two tall ships, the Irving Johnson and Exy Johnson. These 110-foot traditionally rigged vessels were “purpose built” for youth education at sea. In addition to offering a close-up look at marine life, students become part of a working sailboat crew and learn the importance of teamwork.

Sails have already taken place with students from Lennox Middle School (click here to watch video from their trip), Dana Middle School and Emerson Middle School, with a total of 21 sails planned through May 2016.

Reef Check uses “citizen science” to engage local communities in marine conservation. At the start of the SOS program, students are asked to answer a simple question: Why is the ocean valuable? This discussion leads to a hands-on scientific investigation where students will analyze and interpret data collected in the ocean to explain how human impacts play a key role in the health of the ocean and why ocean conservation is critical to our own survival.

“It is shocking that more than 50% of LA County students have never put their toes in the ocean, many do not know how to swim and know little about marine life,” expressed Dr. Gregor Hodgson, Founder & Executive Director of Reef Check Foundation. “By learning to sail a real brigantine sailboat and observing living marine organisms like John Steinbeck did, we hope that SOS students will make an emotional connection with the ocean. Our goal is for students to become ocean ambassadors in their schools and communities.”

The partnership gives students the opportunity to become marine biologists for the day, to experiment, test water for pollution, and to observe fish, invertebrates and live plankton swimming under a microscope. “We hope that some students will eventually enter our advanced marine science training courses to become Reef Check EcoDivers, and join our annual underwater survey of the entire California coast,” said Hodgson.

Upon students' arrival at the waterfront, they receive a packet of illustrated marine science cards to guide their scientific investigation aboard the tall ships. To assist teachers, the SOS program includes classroom and field units designed to support California's Next Generation Science Standards, and pre- and post-program knowledge testing. Students learn about ocean ecosystems, oceanography of waves and currents, and ocean conservation while sailing on a brigantine similar to those used by 19th century explorers.

This educational collaboration seeks to create a new generation of young people who will spread their appreciation for the value of the ocean and marine life.

Black surfperch. Photo: Dan Schwartz (seawindows.org)

By Reef Check California Director Dr. Jan Freiwald

In a recent paper published in the Journal of Ecology, authors Darren Johnson, Reef Check’s Jan Freiwald and Giacomo Bernardi used data on genetic diversity and Reef Check California’s survey data from southern and central California to investigate the strength of population regulation in black surfperch (Embiotoca jacksoni) and how it is affected by their genetic diversity. Population regulation is the mechanism by which natural populations grow or shrink in size depending on their current population size (i.e. number of individuals). This is often related to the resources, predators and other habitat features present at a site. This type of regulation is called density-dependent population regulation because it is dependent on how many individuals are present in a given habitat and ultimately limits the number of individuals that can be supported by an environment. This is an essential process in ecology because it determines how many individuals of a species can be present in an area or habitat. Differences in the ways animals utilize available resources might determine how tightly regulated their populations are. For example, if individuals of the same species can utilize a wide variety of food resources, their population might be less regulated (i.e. their populations can grow larger) than when all individuals compete for the same resource. The way in which individuals use different available resources is linked to their variability, meaning that populations in which individuals differ more in their morphology or physiology will be able to use more resources than populations in which all individuals are similar. As much of the morphological characteristics of individuals are determined by its DNA, it is likely that genetically diverse populations are less tightly regulated and therefore can grow larger than populations with low genetic diversity.

In this study, they evaluated how much of the variation in density-dependent regulation between local black surfperch populations can be explained by their genetic diversity. Black surfperch are a common species on nearshore reefs in southern and central California. Reef Check has monitored this species since 2006 and the authors used monitoring data from 45 sites ranging from San Diego to Monterey.

Genetic diversity is an important source of biodiversity and in this study they showed that it can have a strong influence on how populations grow or shrink. Because genetically diverse populations are spread out more uniformly on the reef, they are able to use more of the available resources and grow faster when resources are available than low diversity populations where individuals are staying closer to each other and therefore are competing for resources more intensely. The results of this study suggest that the size of populations with higher genetic diversity can be up to twice as large compared to that of low-diversity populations if they experience similar environments. This study demonstrates that loss of genetic diversity can have real consequences for the size of fish populations on local reefs. In light of the potential loss of genetic diversity in wild fish populations, for example through overfishing or environmental change, this finding highlights how important it is to not only protect species, but also work to maintain their natural diversity through management and conservation.