My Goldfish is smarter than your 5th grader

Did you ever keep a Goldfish? They really don’t get enough credit. 

Goldfish learning to drive. Photo: Rosen Zyulun via CNN

A research team at Ben-Gurion University developed a FOV (Fish Operated Vehicle) rigged up with LIDAR, a computer, camera, omni-wheels, and an electric motor that gave Goldfish control of the vehicle. 

Each of 6 Goldfish got 10 driving lessons and when they reached their target they were rewarded with food. 

Just like with humans, some of the fish were better at driving than others. 

Previous studies using a saltwater fish, the Cleaner Wrasse, have shown fish to be self aware, and this study takes fish intelligence a step further.

Fish are able to navigate around in their own environments without any issues, but now we know (at least with Goldfish) that they have the cognitive capability to navigate outside its natural environment! This opens up whole new possibilities for studying the navigational abilities of different animals. 

Work done a few years ago found that Sea Turtles off the coast of Africa were able to navigate back to the beaches of their birth, even after getting way off course, using the equivalent of Sea Turtle GPS. 

What do you think we will learn next? 

If you would like to learn more about the Goldfish study, check out this article link: 

https://www.cnn.com/2022/01/10/world/goldfish-drive-intl-scli-scn/index.html

Microplastic Trapping Corals

Which of these catches more plastic particles- sand beds, coral reefs, sea grass beds, or macro-algae?

A study released last month by Jaco C. de Smit et al. looked at how different nearshore habitats trap and collect micro plastics.

They looked how sand/ sediment bed, sea grass, macro algae, and Stylophora (coral) were able to trap 2 different sizes of micro-plastics- 2.5mm and .5 mm.

What they found is that habitats with more complex structures trapped a higher amount of micro-plastics, but the area which trapped the most micro plastics was the sediment, which trapped 1 to 2 times more than any of the other areas.

The reason they believe this happened is because of the near-bed turbulent kinetic energy which is a contributing factor to sediment trapping.

Of the 2 different sizes of microplastics that were trapped, the .5mm particles seemed to be trapped more frequently than the 2.5 mm particles.

We already know micro-plastics are an issue, why does study this matter?

Nearshore ecosystems, like sea grass beds and coral reefs are hugely productive ecosystems and act as nurseries for many species of fish and sharks. According to this study they have large capacity for sequestering plastic. With these areas that are used by animals in vulnerable life stages, being inundated with micro plastics, it is much easier for them to get ingested and cause issues starting from early on. If the inhabitants of these area start to have issues, so too with the areas themselves.

To read their full article search here.

When Home Doesn't Sound Like it Used To

Waves crashing on the beach

What does your home sound like? Is it quiet? Loud? Are there kids playing or dogs barking? Do you hear trains or traffic in the background?

    If you think about it, our homes have a certain sound. Are you having a hard time figuring out what that sound is? Think about the last time you went away and had a hard time falling asleep because you missed the sounds of home.

    Just like our homes and habitats have a certain sound, so to do ocean ecosystems. (Check out my video of Aquarium of the Pacific, Pacific Visions sounds on the reef exhibit to hear what a reef sounds like) Now though, with increasing amounts of anthropogenic influences, aquatic habitats don’t sound the same and animals like Clownfish and whales, who use sound to navigate are having issues. 

While noise pollution might not seem like that big of a deal, it has had increasingly larger impacts on marine life. As anthropogenic noises (air guns, seismic testing, oil drilling platforms, cargo ships, speed boats, pile drivers, etc.) increase, the animals living in the oceans are facing more and more problems.

Consider the last time you were somewhere and you encountered a loud or unpleasant noise. What did you do? Most likely you left the area, which is what some of the larger species like whales and dolphins will do. Animals will often change their course to avoid loud areas like shipping lanes. But what about those smaller sessile species who can’t get away? They have been found to slowly migrate, leaving their native areas all together. Another example of issues it causes is one experienced by Clownfish. In their larval state they live in open water and as they grow they use sounds to help them navigate back to the reefs they will live on. With all the noise pollution, they are unable to tell which direction they need to swim to get to their reef.

  A recently released literature review looked at different studies done around the world with respect to aquatic species and noise pollution. The study’s authors looked at more than 10,000 papers about marine bio-acoustics from the past 20 years with the goal of compiling information that can be used to create policies that will bring about change. 

Researchers point out that noise pollution can cause physical damage to the animals. Some fish can regenerate cells used for auditory purposes, but mammals likely don’t have that ability. 

So, what can be done? While international cargo shipping, and oil drilling is not going to stop, there are changes that can be made to mitigate our impacts on the watery world and its inhabitants.

1. By moving shipping lanes, we can locate them in areas that have as small of an impact as possible. 

2. Reducing the speed of traveling vessels will help to reduce noise pollution they cause. 

3. Changing the types of propellers used to ones that produce fewer cavitation bubbles will quiet them.

4. Creating areas with sound barriers for oil platforms and deep sea drilling can reduce the impacted areas. 

    One of the unique, yet unplanned facets of this review is that the authors got to see the results of reduced noise pollution due to the pandemic slowdowns in commercial shipping. Dr. Carlos Duarte, the paper’s lead author said “Recovery can be almost immediate” as marine mammals and sharks began to return to areas when the shipping traffic slowed during 2020.  

    In the example at the beginning, when considering out home ecosystems, it should be noted that they are not quite, and nor are the oceans. Fish, marine mammals, and other organisms use sound to communicate with croaks, pops, snaps,  and songs. Waves crash, rocks tumble, and water splashes. The goal of this research is not to show us that we need to eliminate the noise we add to the oceans, but to work to make sure that our actions do not take away from the natural sounds of ocean habitats. 

To read the full article search for:  

“The Soundscape of the Anthropocene Ocean”. Carlos Duarte et al. 

Science 05 February 2021 ,Vol 371 Issue 6529

Fish Traveling Via Duck Poo

Male and Female Mallard Duck. Photo by MDC Staff, courtesy Missouri Department of Conservation.

What ways can fish eggs be spread? You thought I was talking about different crackers to use with caviar didn’t you?

In your biology courses, you may have learned there are many different ways seeds, invertebrates, and even larvae of insects are able to disperse over large ranges and to unexpected locations, but can the same be said for fish eggs?

Up until recently the answer to that was no (with the exception of Killifishes), however a paper released in July 2020 by Adam Lovas-Kiss et al. learned something interesting when it comes to waterfowl.

Mallard ducks, a migratory waterfowl, already known for their ability to disperse both aquatic and terrestrial plants were chosen to use in the study and due to their similarity to most teleost fish, researchers chose to use 2 types of fertilized carp eggs- Common Carp and Prussian Carp.

The ducks were individually housed and were each force fed the fertilized eggs (Common Carp in the first experiment and Prussian Carp in the second). After the eggs were ingested, their feces were collected after 1,2,4,6,8,12, and 24 hours.

After the feces were soaked in river water and each sample sifted through this is what they collected:

.2% (8) of the Common Carp eggs

.25% (10) of the Prussian Carp eggs

All but 1 of which, were recovered from the feces within the first hour after ingestion, with the outlier egg being recovered between 4 and 6 hours after ingestion.

Of all the eggs that passed through the Mallards’ digestive systems, 2 Prussian Carp eggs hatched and 1 Common Carp egg hatched! The males passed more eggs than females (15 to 3) and only the eggs passed by the males hatched after they were recovered. It should be noted that all of the hatched fish, both those in the control group and those ingested by the ducks eventually died of fungal infections.

These findings open up and invite many future studies that could look at the traits of fish as well as other waterfowl and their ability to act as a means of dispersal for embryonic fish.

Experimental evidence of dispersal of invasive cyprinid eggs inside migratory waterfowl

Ádám Lovas-Kiss, Orsolya Vincze, Viktor Löki, Felícia Pallér-Kapusi, Béla Halasi-Kovács, Gyula Kovács, Andy J. Green, Balázs András Lukács

Proceedings of the National Academy of Sciences Jul 2020, 117 (27) 15397-15399; DOI: 10.1073/pnas.2004805117

Can Stingrays Hear Sound?

Southern Stingray Photo by Hilary Jaffe

In 2019, Mickle et. al studied 20 different Southern stingrays (Hypanus americanus) in the waters surrounding the Bimini Biological Field Station. They placed underwater speakers in the pen with the stingrays and using a Sony Walkman, they played 5 different low frequency tones.

The 9 males and 11 females were tested individually and were exposed to 5 sound frequencies- 50Hz, 90Hz, 200Hz, 500Hz, and 1000HZ. Using a hydrophone they measured the sound level (in decibels) at 27 different locations inside the stingray’s enclosures.

Since a sound threshold for the rays was previously unknown, they started with 140dB , then depending on the stingray’s swimming behavior** , the sound was increased or decreased by 10dB or 5dB respectively making the levels tested- 130dB, 135 dB, 140dB, 150dB, and 160 dB.

What they found was both male and female stingrays exhibited behavioral differences. The average tone males responded to was 160dB while females responded more to 140dB.

With regard to frequency, males swimming activity increased at 50Hz, 90Hz, 200Hz, and 500 Hz and the females increased their activity at 50Hz, 90Hz, 200Hz, and 1000Hz.

The study looked at the following stingray behaviors- surface breaches, time spent resting, and side-swimming. Both males and females had significant increases in breaching events at 50 Hz, 90 Hz, and 200Hz. Resting rates for males and females decreased at 50Hz, 90Hz, and 200Hz and 50Hz, 90 Hz, 200Hz, and 500Hz respectively. At frequencies of 50Hz, 90 Hz, 200Hz, and 500Hz, both males and females showed increased rates of side-swimming.

If you would like to read their full article, you can find it here.

Mickle, Megan F et al. “Field assessment of behavioural responses of southern stingrays (Hypanus americanus) to acoustic stimuli.” Royal Society open science vol. 7,1 191544. 22 Jan. 2020, doi:10.1098/rsos.191544

** Animal trainers use similar observation to determine their animals level of enrichment and engagement.

Sea Level Rise; Thinking outside the box, Louisiana is planning for the future!

Image from: https://ian.macky.net/pat/map/us/la/la.html

What would you do if your waterfront property was likely to be under water in the near future?

Louisiana is fully aware that a large portion of their southern most residents will need to move inland thanks to rising sea levels, increased frequency of natural disasters and stronger storms. but don’t worry, they have a plan!

Earlier this year the state issued a blueprint to help prepare inland communities for the future influx of people moving away from coastal areas.

This impressive proposal is the first of its kind in the U.S. and while it initially seems like a very lofty goal, when its broken down into the basic components, it makes a lot of sense.

In the proposal, southeast Louisiana is broken down into risk zones- high, moderate, and low- before discussing ways to assist residents who will be moving out of high risk areas, into “receiving communities” located further inland.

The plan discusses ways to help support the growing inland communities as well as ways to strengthen existing coastal towns with stronger buildings codes and storm water management systems. It suggests that certain public services such as schools, grocery and medical be built on floating platforms. Part of the plan even includes diverting parts of the mighty Mississippi River.

In conclusion, yes, this is an expensive ($50 billion) and ambitious plan to be sure, but what is to say that it won’t be successful. No matter where you are, change is inevitable and in order to be successful we must be able to adapt.

If you would like to read more about the plan, Click here.