Greening our thumbs: different types of gardening and why they are important

Did you know that plants make up 80 percent of the food we eat and produce 98 percent of the oxygen we breathe? At home gardening is a great way to learn how important microorganisms, soil, and plants are. Without plants there would be absolutely no food to eat or oxygen to breathe. Gardening also allows you to try new vegetables and fruits that you may have never tried before: such as passion fruit, yellow cucumber, and kohlrabi.

There are many types of gardening that are easy to start at home. Container gardening is great for beginner gardeners and apartment homes. Simply purchase a large pot with your favorite vegetable and start planting. Growing potatoes in large pots is great because when it comes time to harvest you can simply pour out your container and collect your potatoes.

Raised bed gardening is the most popular form of gardening. This method of gardening requires raising the height of the planting area with wooden boards then filling the area with garden soil. The reason why this style of gardening is the most popular is because sometimes the in-ground soil is too difficult to plant in. This can be due to heavily rocky soil and clay soil.

Peppers growing on a raised bed in the Science Mill Food Forest

In-ground gardening is mostly used in agriculture although it can be found in home gardens as well. In-ground gardening is pretty self explanatory; This is when you plant fruits or vegetables directly into the ground. Fun fact, about 38% of the earth's surface is farmed land, which is typically in-ground planting.

Hydroponics and Aquaponics is a cleaner type of gardening that requires absolutely no soil. Hydroponics is the growing of plants in water with the addition of supplemental nutrients and air stones. Aquaponics, like what you’d see at the Aquaponics Greenhouse here at the Science Mill, is just like hydroponics but replaces supplemental nutrients with fish. Instead of the supplemental nutrients, the fish provide the nutrients for the plants with the addition of microorganisms. This way of gardening also consumes less water — up to 10 times less water than traditional agriculture watering methods in fact!

Aquaponics Grow Towers at the Science Mill Aquaponics Greenhouse

Vertical gardening, the last form of gardening that can be accomplished at home, is growing plants in vertical towers. These towers can be purchased from a company or DIYed at home. This type of gardening is most popular in smaller living spaces because it allows you to get creative on where to grow your plants without taking up so much space.

Curious to learn more in person? The Science Mill is opening a new exhibit called a Food Forest this August 19! This exhibit, made possible by HEB’s Our Texas, Our Future initiative and the Favrot Fund, highlights the importance of at home gardening, technology, and regenerative agriculture. We will be opening three brand new raised garden beds that are filled with edible plants as well as unique plants that are so exciting to look at and learn about. Plan your visit today!

Dissecting a Dogfish Shark: 5 Things We Learned

One of the highlights of Shark Week at the Science Mill were the Dogfish Dissections!

Science Mill STEM Education Specialists conducted several dissections throughout the week to give guests a close look into the anatomy of a dogfish shark. Here are some of the questions visitors asked about dogfish sharks during these sessions — and the answers!

WARNING: This post includes photos and videos of the dissection that some readers may be sensitive to!

1. WHY ARE THEY CALLED “DOGFISH”?

   Dogfish sharks get their name not because they are related to or resemble dogs in any way. Rather, they were named as such because they hunt in packs, as dogs do! To satisfy their voracious appetites, dogfish sharks tend to hunt for food in groups that can number in the thousands to feed on anything in their way, like octopus, shrimp, crabs, and even fish that can be two or three times larger than them.

2. JUST KEEP SWIMMING - BUT HOW?

   Most fish have a special organ called a swim bladder which helps them maintain buoyancy without exerting extra energy. Sharks, however, don't have swim bladders; rather, they use oil produced by their livers to control their buoyancy. Proportionally, shark livers can make up 5-25% of the shark’s body weight — in comparison, human livers only take up 2% of the total human body weight!

3. HOW DO DOGFISH SHARKS HUNT FOR PREY?

   One trait that makes sharks apex predators is their ability to detect electricity in the water through their electroreceptors. The muscular movement and twitching that fish and other living organisms make generate electricity, and sharks are able to sense this through their specialized organ.

4. WHAT IS THE DIFFERENCE BETWEEN MALE AND FEMALE DOGFISH SHARKS?

   Generally, female sharks tend to be larger than male sharks. But another way to tell is by checking if the shark has claspers, which is a pair of organs near the pelvic fin that is used during mating.

5. ARE DOGFISH SHARKS ENDANGERED?

   While dogfish sharks can be found in most waters around the world, they are also some of the most heavily fished sharks. This is because they serve as a source of meat (often used in fish and chips in the UK and in shark fin soup), liver oil, fertilizer, and fish food.

Making initial cuts for dissection

Examining the internal anatomy of the shark

Science Mill guests getting a closer look at the dogfish shark specimen

Watch the full dissection below!

What is healthy soil?

Welcome to the third part of #ScienceMillSTEMsday!

This week, let’s take a close look at an important but often underestimated part of the ecosystem: healthy soil!

So what IS healthy soil?

Healthy soil is the foundation of successful agriculture and sustainable ecosystems. As stewards of the land, understanding the indicators of soil health is crucial for farmers, gardeners, and environmentalists alike. Think about it - our lives heavily depend on soil performing vital functions such as supporting crop growth, encouraging biodiversity, and water regulation. By examining key characteristics, we can assess the condition of the soil and make informed decisions to improve or maintain its vitality.

1. Soil Texture and Structure
   Soil texture refers to the proportions of sand, silt, and clay in the soil. Healthy soil has a balanced composition, often referred to as loam, which promotes proper drainage and aeration while retaining sufficient moisture. Furthermore, good soil structure allows for root penetration, nutrient absorption, and microbial activity. Well-aggregated soil, characterized by the formation of stable granules or crumb-like structures, indicates a healthy ecosystem below the surface. Conversely, compacted soil lacking in structure can impede plant growth and reduce water infiltration.

2. Soil Organic Matter
   The presence of organic matter in the soil is a strong indicator of its health. Organic matter, such as decomposed plant and animal materials, enhances soil fertility, moisture retention, and nutrient availability. It serves as a food source for beneficial soil organisms, including bacteria, fungi, and earthworms, which help break down organic matter and contribute to nutrient cycling. Darker soil coloration usually suggests a higher organic matter content. Regular additions of compost or organic amendments can boost soil organic matter, improving its overall health and resilience.

3. Soil pH
   Soil pH is a measure of its acidity or alkalinity and greatly influences nutrient availability to plants. Most crops prefer a slightly acidic to neutral pH range. Acidic soils limit the availability of essential nutrients, while alkaline soils may cause nutrient imbalances. Regular soil testing helps identify the pH level, enabling growers to adjust it through amendments. Maintaining an optimal pH balance is essential for efficient nutrient uptake, maximizing crop productivity, and fostering a diverse soil microbial community.

4. Soil Moisture
   Adequate soil moisture is essential for plant growth and microbial activity. Healthy soil should possess a good water-holding capacity while allowing excess water to drain away. The ability to retain moisture depends on factors such as soil texture, organic matter content, and compaction. Soil that remains too dry or too waterlogged can negatively impact root development and reduce the availability of essential nutrients. Regular monitoring of soil moisture levels helps optimize irrigation practices and conserve water resources.

5. Biodiversity and Soil Life
   When you walk on soil, you probably don’t realize the incredible biodiversity that exists right beneath your feet! A thriving soil ecosystem teems with a diverse range of organisms, including bacteria, fungi, nematodes, earthworms, and insects. The presence of these beneficial organisms indicates a healthy and balanced soil environment. These organisms contribute to nutrient cycling, decomposition of organic matter, and pest control. Earthworms, for example, help improve soil structure through their burrowing activities. Promoting biodiversity aboveground, such as through crop rotation and cover cropping, can also have a positive impact on soil health by providing diverse organic inputs and fostering a symbiotic relationship with soil life.

PRINCIPLES OF SOIL HEALTH

As you can tell by now, healthy soil is important for many reasons. However, not all soils are healthy; in fact, there are numerous threats to soil health, which include erosion (due to water, wind, or tillage), carbon loss, nutrient imbalance, among others.

To create or maintain healthy soil, there are four basic principles:

1. Maximize biodiversity - this helps ensure a balanced habitat for soil organisms. Lengthening crop rotation, adding perennials, planting cover crops, and having grazing livestock are some ways of doing this.

2. Minimize disturbance - disturbance can take the form of physical disturbance (like tilling), chemical (which can disrupt the food web), or biological (which can be a result of low biodiversity). Minimizing this allows the soil time to recuperate and regulate.

3. Maximize living roots - roots nourish the microbes in the soil by providing food and releasing nutrients that contribute to overall soil health, such as by increasing the soil’s level of organic matter.

4. Maximize soil cover - soil cover refers to vegetation, crops, or crop residues that cover the soil which play an important role in controlling erosion and keeping the soil cool.

---

GIVEAWAY

Every Wednesday this July, the Science Mill will be on We Are Austin to talk about awesome science topics and an activity you can do at home! Post a photo or video of you/your family doing the activity on either Facebook OR Instagram and get the chance to win a family membership for 4 to the Science Mill!

MECHANICS:

1. Like our giveaway post and follow/like our Facebook and Instagram pages

2. Post your entry on Facebook or Instagram and tag it with #ScienceMillSTEMsday

For this week, learn more about the microscopic world around you by extracting nematodes from the soil! Nematodes are very small worms commonly found in soil, especially around plant roots. They help regulate pest organisms and even help release nutrients beneficial to plants! Through this simple at home activity, which only requires any soil sample, some facial tissues, mesh, and a pan with water, you can test your sample for the presence of nematodes!

Source: USDA Agricultural Research Service

Simply document your experiment, post it on Facebook or Instagram, and tag us to participate in this week’s #ScienceMillSTEMsday activity!

Simply Fintastic: The Top 10 Sharks That Aren’t a Great White

Welcome to the second part of #ScienceMillSTEMsday!

What is a shark’s favorite song?

Don’t Stop, Be-reef-ing!

HAPPY SHARK WEEK AT THE SCIENCE MILL!

Sharks! What’s not to love about them? These sea-faring creatures are some of the most unique animals on Earth. While many movies depict sharks as violent predators of the ocean, most sharks are completely harmless to humans! Of the 500+ shark species around the world, only 12 are considered dangerous to humans. Sharks are very important to their ecosystems and help promote biodiversity by being indiscriminate predators. 

This list highlights some of the coolest sharks around that we share our waters with. 

10) Hammerhead Sharks

Topping off our list at number 10 is the Hammerhead shark. There are only 9 Hammerhead shark species in the world. The T-shape of its head is referred to as a cephalofoil. Scientists are still unsure why this species of shark has this feature, but it does provide superior binocular vision and depth perception than what other sharks have. The cephalofoil is also thought to help with maneuverability, sensory reception, and prey manipulation. Hammerhead sharks are also unique in their hunting patterns. During the day, they are known to hunt in packs of up to 100. At night, the transition to solitary hunters which is the more commonly observed hunting pattern of most sharks.

9) Greenland Shark

Of the 500+ species of sharks around the world, deep sea sharks are the most unique! There are a multitude of shark species that inhabit deep sea levels around the world. Greenland Sharks live in the Arctic and sub-Arctic waters of the North Atlantic and Arctic oceans. They live in the deepest oceans in the world and have been spotted 7,200 feet below sea level. Greenland sharks also have the longest lifespan of all sharks - typically living up to 250-500 years. Greenland sharks also have a unique migration pattern. Instead of migrating over horizontal distances, they migrate throughout the year based on vertical water level. They migrate to shallow waters in the winter and return to deep sea levels in the summer.

8) Tiger Shark

The tiger shark is second only to the Great White in predation. It is known to have the widest food spectrum of all sharks - preying on turtles, squids, fish, birds, dolphins, crustaceans, and other sharks. It gets its name from the dark stripes on its side, but these stripes fade as the shark matures. The orca is the only known predator of tiger sharks. Tiger sharks also have a unique hunting tool called countershading. When prey looks up at a Tiger shark above them, the white underbelly camouflages the shark against the sunlight. 

7) Thresher Shark

While Thresher sharks live in temperate and tropical oceans around the world, only 3 species of these sharks exist today, and they are considered vulnerable to extinction. They are named after their unique caudal fins, which can grow to be the same size as the shark’s body. They use their Thresher tail to stun prey, primarily tuna and mackerel fish. They are also some of the fastest shark species alive. They can swim up to 30 mph but can whip their tail close to 80 mph!

6) Goblin Sharks

Some of the spookiest sea creatures around, Goblin sharks are deep sea creatures that live at a minimum of 330 ft (100m) below the ocean surface. It is sometimes referred to as a “living fossil” since it is the only existing member of the Mitsukurinidae family, which has a lineage dating back to 125 million years ago. Its unique jaw shape allows it to quickly jut out and snag their prey. The “blade” shape of its snout actually decreases in size with age as the shark gets older. 

5) Dogfish Sharks

The Dogfish is the most common shark species on the planet. There are 119 different species of dogfish, making it the second largest order of sharks on the planet. They live in coastal waters around the world. They are called “dogfish” because they are known to hunt in packs of up to 100. The Spiny Dogfish species have a spine that protrudes next to their dorsal fins. These spines actually produce venom, which is exceptionally rare for sharks! Dogfish are some of the most heavily fished sharks in the world for their use in meals in Southeast Asia and Western-Northern Europe. They are also migratory sharks. Pacific Dogfish have been recorded to migrate over 5,000 miles (8,000 km) from Washington state to Japan. 

• We’ll be dissecting dogfish all week at the Science Mill during Shark Week! Stop on by Tuesday (7/11), Thursday (7/13), or Friday (7/14) to learn more about the dogfish!

4) Nurse Sharks

Nurse sharks are primarily bottom-dwellers and prey on small fish, stingrays, crustaceans, and mollusks. While they have a reputation of being slow-moving and the “couch potatoes” of the ocean floor, they can actually move pretty fast if they want to! When in danger, nurse sharks can flee at up to 25 mph. They are listed as a vulnerable species and primarily live in tropical and subtropical waters in the Pacific and Atlantic Oceans.

3) Basking Sharks

They may be huge, and their large open mouths may be scary to some, but these sharks actually pose no threats to humans!While they are related and often confused as Great White sharks, basking sharks are filter feeders and only eat plankton. Due to their size, they are heavily fished commercially for their fins and liver oil. Their teeth are very small, but can number up to 100 per row of teeth. 

2) Angel Sharks

Like nurse sharks, angel sharks are bottom-dwellers that live on the coastal ocean floors near every continent on the planet. These sharks excel at camouflage, blending into the sandy floors of coastal waters hunting their prey of small fish and crustaceans. While they are not aggressive, they have been known to attack in retaliation if they have been stepped on. 

1) Mako Sharks

Mako Sharks are recorded to be the fastest sharks in the world. The shortfin mako shark has a cruising speed of 31 mph, but can reach speeds of 46 mph! They are listed as an endangered species and primarily eat a wide range of prey consisting of mackerel, tuna, tortoises, and other sharks. They are unique in their hunting patterns in that they will use their speed to lunge upwards towards their prey. 

Now that you know ten more shark species, do you have a favorite?

---

GIVEAWAY

Every Wednesday this July, the Science Mill will be on We Are Austin to talk about awesome science topics and an activity you can do at home! Post a photo or video of you/your family doing the activity on either Facebook OR Instagram and get the chance to win a family membership for 4 to the Science Mill!

MECHANICS:

1. Like our giveaway post and follow/like our Facebook and Instagram pages

2. Post your entry on Facebook or Instagram and tag it with #ScienceMillSTEMsday

For this week, make a creative depiction of any shark of your choice from OCEARCH! You can draw, paint, use cardboard or recycled materials, or even code your shark! Snap a photo of your creation, post it on Facebook or Instagram and tag it with #ScienceMillSTEMsday. Check out these examples!

One winner will be randomly selected on July 28. They will be contacted only by the official Science Mill Facebook or Instagram accounts. Good luck and happy learning!