The article linked below outlines the impact of human population growth on global marine fisheries. It has been well-established through scientific research that as people become wealthier, they consume more protein. And as Earth’s human population continues to grow, the pressure on fisheries becomes two-fold: not only are there more people fishing (population growth), but those people are becoming wealthier (economic growth) and eating more seafood per person. This article ties in brilliantly to ESS Topic 3 – Human Populations, Resource Use, and Carrying Capacity.
The idea is quite simple, actually: Rural families who can’t afford the high costs in setting up a traditional solar electricity system are able to pre-pay for a certain amount of electricity generated by the solar kit. Once they’ve used the electricity paid for, the kit shuts off access until they make another payment – just like the scratch-off cards for mobile phone vouchers we use here in Dar es Salaam – and payments can be made via M-Pesa or similar services. When they have the cash, they buy more electricity, and once they’ve paid for the full kit, it continues to generate electricity for them for free!
Below is the recent test on ESS Topics 1, 7, and 2.1 – 2.3. The original test and the mark scheme are included as a single document and consist of real IB questions from past papers.
The red ovals highlight the key words in the questions, and the blue rectangles identify the parts of the responses which earn marks from the examiners. Please use this test as a study guide for future tests, such as this year’s final exam and next year’s mock exam.
We are 1 week from the summative unit test in grade 9 science, which means it’s time to start revising. Here’s a list of the major topics you’re likely to find on the test.
Cell structure and function
Plant vs animal
Energy flow through ecosystems
Nutrient cycles within ecosystems
Photosynthesis and respiration
Levels of organization
There will be several skills assessed on the test: recalling scientific facts (vocabulary and definitions, labeling diagrams), explaining scientific concepts, analyzing results, and evaluating trends in experimental data. Make sure you know this stuff well!
Even the snakes at my house are curious! (Image credit: Brad Kremer)
Environmental scientists, national park wardens, reserve managers, and conservation officers are the people making the decisions about Tanzania’s abundant wildlife resources. Many of the choices they make about the areas and organisms they protect are based on political and/or economic considerations, but most of those decisions will have at least some foundation in scientific knowledge.
How do we know which living resources are present in a national park or reserve? How do we know the number of elephants or eland or egrets in a wildlife management area? These are some essential questions for anyone charged with sustainably managing a country’s natural resources. Luckily for all of us, science has some answers!
The Lincoln Index is a tool used to estimate populations of mobile organisms in an ecosystem. The Lincoln index answers the question, “How many?” There are 4 key steps to properly conducting a Lincoln Index survey:
Capture: systematically catch organisms without harming them
Lincoln Index formula. See the syllabus for a further explanation on its use.
Mark: mark the organisms in a way that does not harm them
Release: let them return to their natural habitat
Recapture: catch another
These 4 steps will provide some key data points, which can be plugged into a mathematical formula, shown at right, which estimates the total size of the population in the area sampled.
Another highly useful tool for measuring biotic components of ecosystems is the Simpson Index, or the Simpson Reciprocal Index. The Simpson Index measures the diversity of an ecosystem. Simpson accounts for both aspects of diversity, as defined in our ESS syllabus: species richness (the total number of species present) and species evenness (the number of individuals of each species present). The process for calculating Simpson’s D-value is a little more complicated than that for calculating Lincoln, but not much. Please check the ESS syllabus for details.
Simpson’s Diversity Index. See the syllabus for further details on its use.
We’ll be simulating 3 different ecosystems in class over the next couple of days, so you should have plenty of opportunity to test out these formulae and manipulate some of the variables within them. Both of these procedures will help you tremendously on the ESP week of field work in Zanzibar. (Hint, Hint)
I’ve posted this first article before – from the UN Office on Drugs and Crime – which outlines the links between ivory from east Africa and narcotics in Asia. The embedded version is the short one, and the full version is available to download here: Ivory and Organized Crime in East Africa.PDF
The following item is a dissertation research paper by Justine Braby, an Environmental Law Postgraduate candidate at the University of Cape Town. In it, she examines how effective the CITES ban on ivory has been since implemented. CITES is the Convention on International Trade in Endangered Species, a global framework for reducing and/or eliminating the trade in all endangered organisms for commercial gain. The CITES website has a lot of very specific information directly relating to the ESS Topic 4 – Conservation and Biodiversity, as well as the Grade 9 poaching project. I recommend you check out both the articles posted here, as well as the CITES page.
This report, part II in a series, looks at likely impacts of 2°C and 4°C warming across three vulnerable regions.
It describes risks to agriculture and livelihoods in Sub-Saharan Africa, the rise in sea-level and devastation to coastal areas likely in South East Asia, and water extremes facing South Asia.
Turn Down the Heat warns that poor coastal urban communities are among the most vulnerable to climate change.
As a poor, coastal, urban community in Sub-Saharan Africa, Dar fits this description perfectly. Jim Yong Kim, President of the World Bank Group, talks about the perils of climate change in the brief video embedded below.
Here are a few more links relating to this topic, which seems to be all over the news lately.
This first item, from the Wildlife Conservation Society and the IUCN (International Union for the Conservation of Nature, the same organization which just declared the Western Black Rhino officially extinct) is a publication called Pachyderm. In it, there are several case studies about both rhinos and elephants, including some information on using micro-chemical evidence to trace the origin of poached ivory. Here’s the link to the complete PDF.
Edge of Existence is a website I recently stumbled across, and I think it has a lot of well-researched information about a lot of issues in wildlife conservation. EDGE stands for “Evolutionarily Distinct and Globally Endangered” species – unique creatures threatened by human activities around the world. Their page for elephants, linked here, has some really useful information on elephants’ role in maintaining the savanna ecosystem, conservation initiatives currently in use, links to organizations involved in elephant conservation, and references to more scientific information about Loxodonta africana.
A younger-looking Sir David Attenborough with lemurs from Madagascar. (Screen capture image from www.bbc.co.uk)
And finally, no wildlife conservation unit would be complete without at least one video from Sir David Attenborough (probably my favorite scientist of all time). The short video clip linked here is from Sir David’s earlier work in Madagascar, so he looks a bit different than most of you are used to seeing him. It was originally released in 1961 – 52 years ago!