1 General Overview of Aquaculture Definitions The oyster example would fit the definition of What is aquaculture? extensive aquaculture where the culturist has little Aquaculture can be defined in a number of ways. control over the system but merely provides a more The one I have used for many years is: aquaculture suitable habitat for the animals; in this case the is the rearing of aquatic organisms under controlled spreading of oyster shell. The larval oysters (called or semi-controlled conditions. That is a fairly sim­ spat) may come from natural spawning or may be ple, but comprehensive definition. An abbreviated produced and settled on oyster shell (cultch) in a definition is that aquaculture is: underwater agri- hatchery, which increases the level of interaction culture. The longer of the two definitions can be between the culturist and the target species and broken down into three major components: thus modifies the level of intensity in the overall production process. ● Aquatic refers to a variety of environments, When operating a recirculating system, the aqua­ including fresh, brackish, marine and hyper­ culturist exerts a high level of control and the system saline waters. Each environment is defined on is called intensive. Even just placing a culture unit the basis of its salinity (most simply the amount in the environment represents a means of control­ of salt that is dissolved in the water). Salinity ling the animals that are being reared. Cages and is discussed in some detail in Chapter 4. net pens are examples (see Chapter 3). There are a ● Aquatic organisms refers to any organisms that number of other approaches that lie somewhere in live or can live in water. A branch of aquacul­ between the extremes of extensive and intensive. ture called mariculture is reserved for aquatic Those are often referred to as semi­intensive sys­ organisms reared in saltwater (which can range tems. Systems that go beyond intensive are called from low to hypersaline water). Aquaculture hyperintensive; so we can view aquaculture organisms of interest with regard to human approaches as ranging broadly from very simple to food include a wide variety of plants, inverte­ highly complex, or – perhaps more precisely – as brates and vertebrates. In the plant kingdom, ranging from systems that employ little technology we include algae along with higher plants and, to those that rely heavily upon technology. It can be in some cases, terrestrial plants that are grown argued that, as the amount of technology involved using a method called hydroponics or aquapon­ in the culture system increases, so does the amount ics (discussed in Chapter 9). of control that the culturist has over the system. ● Controlled or semi­controlled refers to the fact One can also argue that as the level of technology that the aquaculturist is growing one or more employed increases, so does the probability of sys­ types of aquatic organisms in an environment tem failure, since there are more things that can, that has been altered to a greater or lesser extent and often will go wrong as you add complicated from the environment in which the species is mechanics, work in harsher and harsher environ­ normally found. The amount of control that is ments (like in the open ocean) and add electronic exerted by the aquaculturist can vary signifi­ systems (automatic feeders, water quality monitor­ cantly. Spreading oyster shell on the bottom of a ing, alarm systems, etc., discussed later in this vol­ bay to provide a surface for settlement of larval ume). Persons who engage in aquaculture may be oysters is at one extreme, while operation of an called aquaculturists, independent of the type of water indoor hatchery that incorporates a water­reuse system that is employed, or mariculturists, who system is at the other (see Chapter 3). work with aquatic species in saline environments © Robert R. Stickney 2017. Aquaculture: An Introductory Text, 3rd Edn (R.R. Stickney) 1 (from low salinity to hypersaline waters). Depending if possible, some basic engineering. Mechanical upon the type of organism(s) being reared, the cul­ engineering is certainly beneficial and courses in turist may also be referred to as a fish farmer, such subjects as hydrology and sanitary engineer­ shrimp farmer, clam farmer, etc., or by an even ing can be useful. For many practising aquacultur­ more limited restrictive title, such as rainbow trout ists, including those involved in certain types of producer, catfish farmer, Atlantic halibut farmer, etc. research, the ability to drive trucks and tractors As you read this book, you will run into the and having some skills in association with plumb­ word seafood periodically. When I use that word, ing, electrical wiring, welding, painting and carpen­ you need to think in terms of all edible aquatic spe­ try are beneficial, if not required. Experience cies, not just those that are captured from, or cul­ pouring concrete will also often come in handy. tured in, saltwater. When you think about it, A list of skills and disciplines which are often useful seafood restaurants usually serve both marine and to aquaculturists and that reiterates what you have freshwater species. There are exceptions, of course, just read is shown in Box 1.1. A high level of exper­ but in general, a mixture of marine and freshwater tise in each of the items on the list is not required, species is typical. So seafood includes finfish, inver­ though familiarity with the majority of them will tebrates and often algae (such as in sushi wrappers, certainly be of value. I should point out that there salads and various other dishes). are a number of those disciplines in which I did While the above definitions are fairly simple, not/do not have much, if any, background. In fact, they embrace an extremely broad and complex topic there were no courses in general aquaculture avail­ that involves a broad array of scientific disciplines able where I went to college. You probably will not and business management, along with engineering, be able to begin a career in aquaculture having had economics, accounting and trade skills. A serious all the background you need, but you will quickly student of aquaculture should have experience (and acquire the knowledge and/or skills you need or preferably have taken formal courses) in mathemat­ you will surround yourself with a complement of ics, chemistry (through at least organic), physics, people who have the skills you lack. If you do not, biology, business management and economics and, it could be a difficult uphill battle to become successful. Box 1.1. A sampling of the skills and disciplines that are often of considerable value to the aquaculturist. Skills: Plumbing Carpentry Welding Electrical wiring Computer (word processing, spreadsheets, control systems) Painting Concrete pouring and finishing Operating equipment such as tractors, backhoes, bulldozers Truck driving (pickup trucks and larger) Courses: Business management (bookkeeping, accounting, marketing) Basic economics Chemistry (particularly water chemistry and organic chemistry) Biology (ichthyology, invertebrate zoology, physiology) Physics Geology (particularly marine) Limnology and/or oceanography Nutrition (animal) Aquatic animal disease Basic engineering principles Hydrology Aquaculture and/or mariculture 2 Chapter 1 One thing you should take away from this book is in ornamental aquaculture were made by hobbyists that aquaculture is not a science or a discipline that and commercial producers who began working to stands on its own. It is made up of many disciplines develop culture methods for species that could not that come together and are required if a venture is be taken through their entire life cycle in captivity to become economically viable. An important but had to be captured from the wild. The tech­ attribute of the successful aquaculturist is also a niques often appeared in aquarium magazines or, high level of common sense. when developed by a commercial ornamental spe­ cies producer, were not revealed so that the person or company would, at least for a time, have a What is involved? monopoly on the methodology. You can be sure The aquaculturist is often faced with making on­ that if one person figures out/solves a problem, the­spot decisions. The fish are at the surface look- such as how to breed a particular species of cleaner ing like they are gasping for air! What should I do? shrimp, someone else will also figure it out. This is where common sense comes into play. There Another interest of aquaculturists is production is no time to call in an expert and, if there were, of non­food and non­ornamental species that have what type of expert would you call? If you know commercial value. Those include pearl oysters who to call, do you know how to describe the (marine) and freshwater pearl mussels. Aquaculturists problem in sufficient detail so that the person can are also raising bath sponges, live rock and corals. provide a reasonable solution for you? Questions Live rock is produced by placing terrestrial rocks, that you may be asked by the person you call are: such as limestone, in the marine environment and Is there the possibility of a chemical in the water leaving them until they become colonized with such as a pesticide that is causing the problem? Can various benthic organisms. Then the rocks can be you tell if your animals have a disease? You also do sold into the marine aquarium trade. As in the case not have time to study the situation. You have to of fingerprints, no two live rocks are the same. take action based upon your knowledge and, again, They vary in terms of the species present and the a good measure of common sense. As you will see density of those species.